Dvips
*****

This manual documents Dvips version 5.999 (February 2019), a program to
translate a DVI file into PostScript.  You may freely use, modify and/or
distribute this file.

1 Why use Dvips?
****************

The Dvips program has a number of features that set it apart from other
PostScript drivers for TeX.  This rather long section describes the
advantages of using Dvips, and may be skipped if you are just interested
in learning how to use the program.  See Installation, for details
of compilation and installation.

   The Dvips driver generates excellent, standard PostScript, that can
be included in other documents as figures or printed through a variety
of spoolers.  The generated PostScript requires very little printer
memory, so very complex documents with a lot of fonts can easily be
printed even on PostScript printers without much memory, such as the
original Apple LaserWriter.  The PostScript output is also compact,
requiring less disk space to store and making it feasible as a transfer
format.

   Even those documents that are too complex to print in their entirety
on a particular printer can be printed, since Dvips will automatically
split such documents into pieces, reclaiming the printer memory between
each piece.

   The Dvips program supports graphics in a natural way, allowing
PostScript graphics to be included and automatically scaled and
positioned in a variety of ways.

   Printers with any resolution are supported, even if they have
different resolutions in the horizontal and vertical directions.  High
resolution output is supported for typesetters, including an option that
compresses the bitmap fonts so that typesetter virtual memory is not
exhausted.  This option also significantly reduces the size of the
PostScript file and decoding in the printer is very fast.

   Missing fonts can be automatically generated if Metafont exists on
the system, or fonts can be converted from GF to PK format on demand.
If a font cannot be generated, a scaled version of the same font at a
different size can be used instead, although Dvips will complain loudly
about the poor aesthetics of the resulting output.

   One of the most important features is the support of virtual fonts,
which add an entirely new level of flexibility to TeX.  Virtual fonts
are used to give Dvips its excellent PostScript font support, handling
all the font remapping in a natural, portable, elegant, and extensible
way.  Dvips even comes with its own Afm2tfm program that creates the
necessary virtual fonts and TeX font metric files automatically from the
Adobe font metric files.

   Source is provided and freely distributable, so adding a
site-specific feature is possible.  Adding such features is made easier
by the highly modular structure of the program.

   There is really no reason to use another driver, and the more people
use Dvips, the less time will be spent fighting with PostScript and the
more time will be available to create beautiful documents.  So if you
don't use Dvips on your system, get it today.

   Tom Rokicki wrote and maintains the original Dvips program.

2 Installation
**************

Installing Dvips is mostly the same as installing any Kpathsea-using
program.  Therefore, for the basic steps involved, see
Installation (kpathsea).

   For solutions to common installation problems and information on how
to report a bug, see the file 'kpathsea/BUGS' (see Bugs (kpathsea)).
For solutions to Dvips-specific problems, see Debug options.  Also
see the Dvips home page at <http://www.radicaleye.com/dvips>.

   Dvips does require some additional installation, detailed in the
sections below.  Also, to configure color devices, see Color device configuration.

2.1 'config.ps' installation
============================

Dvips has its own configuration files: a file 'config.ps' for sitewide
defaults, and a file 'config.PRINTER' for each printer (output device).
Since these are site-specific, 'make install' does not create them; you
must create them yourself.

   (These Dvips configuration files are independent of the Kpathsea
configuration file 'texmf.cnf' (see Config files (kpathsea)).

   Dvips configuration files contents and searching are described fully
in Config files.  The simplest way to create a new configuration
file is to copy and modify the file 'dvipsk/contrib/config.proto',
seasoning with options to your taste from Config files.  Here is
'config.proto' for your reading pleasure:
     % Prototype Dvips configuration file.  (Public domain.)

     % How to print, maybe with lp instead lpr, etc.
     o |lpr

     % Default resolution of this device, in dots per inch.
     D 600

     % Metafont mode.  (This is completely different from the -M command-line
     % option, which controls whether MakeTeXPK is invoked.)  Get
     % <ftp://ftp.tug.org/tex/modes.mf> for a list of mode names.  This mode
     % and the D number above must agree, or MakeTeXPK will get confused.
     M ljfour

     % Memory available. Download the three-line PostScript file:
     %   %! Hey, we're PostScript
     %   /Times-Roman findfont 30 scalefont setfont 144 432 moveto
     %   vmstatus exch sub 40 string cvs show pop showpage
     % to determine this number. (It will be the only thing printed.)
     m 3500000

     % Correct printer offset. You can use testpage.tex from the LaTeX
     % distribution to find these numbers. Print testpage.dvi more than once.
     O 0pt,0pt

     % Partially download Type 1 fonts by default.  Only reason not to do
     % this is if you encounter bugs.  (Please report them to
     % <tex-k@tug.org> if you do.)
     j

     % Also look for fonts at these resolutions.
     R 300 600

     % With a high resolution and a RISC cpu, better to compress the bitmaps.
     Z

     % Uncomment these if you have and want to use PostScript versions of the
     % fonts.
     %p +cmfonts.map
     %p +lafonts.map
     %p +cyrfonts.map
     %p +eufonts.map

     % To include another configuration file here.
     %c FILENAME

     % You will also want definitions for alternative paper sizes -- A4,
     % legal, and such.  Examples in contrib/papersize.level2 and
     % contrib/papersize.simple.

2.2 PostScript font installation
================================

To use PostScript fonts with TeX and Dvips, you need both metric files
('.tfm' and '.vf') and the outlines ('.pfa' or '.pfb').  See Font concepts.
Current TeX systems come with support for 35 base
PostScript fonts and many more.

   If you have additional PostScript fonts, you can make them available
to Dvips by (1) giving them appropriate filenames; and (2) running
Afm2tfm (see Making a font available) to make TFM and VF metrics for
TeX and Dvips to use.  Also add them to 'psfonts.map' (see
psfonts.map); this file must contain everything available in the
system.  The 'updmap' program is usually used to maintain 'psfonts.map';
run 'updmap --help' for lots of information about how it works.

2.3 Ghostscript installation
============================

Ghostscript is a PostScript interpreter freely available to end-users,
originally written by Peter Deutsch.  It can read the PostScript
produced by Dvips and render it on your monitor, or for another device
(e.g., an Epson printer) that does not support PostScript, or in PDF
format.  The latest version is available via <http://ghostscript.com>.

   The program Ghostview, originally written by Johannes Plass and Tim
Theisen, provides typical previewing capabilities (next page/previous
page, magnification, etc.).  It requires Ghostscript to run, and files
in structured Postscript, specifically with '%%Page' comments (no 'N' in
'config.ps').  The current version is known as GV, and is available from
<http://www.gnu.org/software/gv>.

2.4 Diagnosing problems
=======================

You've gone through all the trouble of installing Dvips, carefully read
all the instructions in this manual, and still can't get something to
work.  The following sections provide some helpful hints if you find
yourself in such a situation.

   For details on effective bug reporting, common installation problems,
and 'mktexpk' problems, see Bugs (kpathsea).

   A good first debugging operation is to set the environment variable
'DVIPSDEBUG', which will display any configuration and map files read by
Dvips.  This way you can be sure it's finding the files and settings you
expect.

2.4.1 Debug options
-------------------

The '-d' flag to Dvips helps in tracking down certain errors.  The
parameter to this flag is an integer that tells what errors are
currently being tracked.  To track a certain class of debug messages,
specify the appropriate number given below; if you wish to track
multiple classes, sum the numbers of the classes you wish to track.  To
track all classes, you can use '-1'.

   You can also set the environment variable 'KPATHSEA_DEBUG' instead of
using '-d'.  Some of these debugging options are actually provided by
Kpathsea (see Debugging (kpathsea)).

   The classes are:

1
     specials
2
     paths
4
     fonts
8
     pages
16
     headers
32
     font compression
64
     files
128
     (omitted)
256
     config files
512
     Kpathsea 'stat' calls
1024
     Kpathsea hash table lookups
2048
     Kpathsea path element expansion
4096
     Kpathsea path searches

2.4.2 No output at all
----------------------

If you are not getting any output at all, even from the simplest
one-character file (for instance, '\ \bye'), then something is very
wrong.  Practically any file sent to a PostScript laser printer should
generate some output, at the very least a page detailing what error
occurred, if any.  Talk to your system administrator about downloading a
PostScript error handler.  (Adobe distributes a good one called
'ehandler.ps'.)

   It is possible, especially if you are using non-Adobe PostScript,
that your PostScript interpreter is broken.  Even then it should
generate an error message.  Dvips tries to work around as many bugs as
possible in common non-Adobe PostScript interpreters, but doubtless it
misses a few.  PowerPage Revision 1, Interpreter Version 20001.001, on a
Mitsubishi Shinko CHC-S446i color thermal dye sublimation printer is
known to be unable to print with any but builtin fonts.

   If Dvips gives any strange error messages, or compilation on your
machine generated a lot of warnings, perhaps the Dvips program itself is
broken.  Try using the debug options to determine where the error
occurred (see Debug options).

   It is possible your spooler is broken and is misinterpreting the
structured comments.  Try the '-N' flag to turn off structured comments
and see what happens.

2.4.3 Output too small or inverted
----------------------------------

If some documents come out inverted or too small, probably your spooler
is not supplying an end of job indicator at the end of each file.  (This
commonly happens on small machines that don't have spoolers.)  You can
force Dvips to do this with the '-F' flag (or 'F' config file option),
but this generates files with a terminating binary character
(control-D). You can also try using the '-s' flag (or 's' config file
option) to enclose the entire job in a save/restore pair.  See
Command-line options, and Config files.

2.4.4 Error messages from printer
---------------------------------

If your printer returns error messages, the error message gives very
good information on what might be going wrong.  One of the most common
error messages is 'bop undefined'.  This is caused by old versions of
Transcript and other spoolers that do not properly parse the setup
section of the PostScript.  To fix this, turn off structured comments
with the '-N' option, but it'd be best to get your spooling software
updated.

   Another error message is 'VM exhausted'.  Some printers indicate this
error by locking up, others quietly reset.  This is caused by Dvips
thinking that the printer has more memory than it actually does, and
then printing a complicated document.  To fix this, try lowering the 'm'
parameter in the configuration file; use the debug option to make sure
you adjust the correct file.

   Other errors may indicate you are trying to include graphics that
don't nest properly in other PostScript documents, among other things.
Try the PostScript file on a QMS PS-810 or other Adobe PostScript
printer if you have one, or Ghostscript (see Ghostscript installation);
it might be a problem with the printer itself.

2.4.5 Long documents fail to print
----------------------------------

This is usually caused by incorrectly specifying the amount of memory
the printer has in the configuration file; see the previous section.

2.4.6 Including graphics fails
------------------------------

The most common problem with including graphics is an incorrect bounding
box (see Bounding box).  Complain to whoever wrote the software that
generated the file if the bounding box is indeed incorrect.

   Another possible problem is that the figure you are trying to include
does not nest properly; there are certain rules PostScript applications
must follow when generating files to be included.  The Dvips program
includes work-arounds for such errors in Adobe Illustrator and other
programs, but there are certainly applications that haven't been tested.

   One possible thing to try is the '-K' flag which strips the comments
from an included figure.  This might be necessary if the PostScript
spooling software does not read the structured comments correctly.  Use
of this flag will break graphics from some applications, though, since
some applications read the PostScript file from the input stream,
looking for a particular comment.

   Any application which generates graphics output containing raw binary
(not ASCII hex) will probably fail with Dvips.

3 Invoking Dvips
****************

Dvips reads a DVI file as output by (for example) TeX, and converts it
to PostScript, taking care of builtin or downloaded PostScript fonts,
font reencoding, color, etc.  These features are described in other
chapters in this document.

   There many ways to control Dvips' behavior: configuration files,
environment variables, and command-line options.

3.1 Basic usage of Dvips
========================

To use Dvips at its simplest, simply type

     dvips foo

where 'foo.dvi' is the output of TeX that you want to print.  The
default output is to a corresponding file 'foo.ps'; Dvips may also have
been locally configured to output directly to a printer by default.

   If you use fonts that have not been used on your system before, they
may be automatically generated; this process can take a few minutes, so
progress reports appear by default.  The next time that document is
printed, these fonts will have been saved in the proper directories, so
printing will go much faster.  (If Dvips tries to endlessly generate the
same fonts over and over again, it hasn't been installed properly.
See Unable to generate fonts (kpathsea).)

   Many options are available (see the next section).  For a brief
summary of available options, just type

     dvips --help

3.2 Command-line options
========================

Dvips has a plethora of command line options.  Reading through this
section will give a good idea of the capabilities of the driver.

3.2.1 Option summary
--------------------

Here is a handy summary of the options; it is printed out when you run
Dvips with no arguments or with the standard '--help' option.

Usage: dvips [OPTION]... FILENAME[.dvi]
Convert DVI input files to PostScript.
See http://tug.org/dvips/ for the full manual and other information.

Options:
-a*  Conserve memory, not time       -A   Print only odd (TeX) pages
-b # Page copies, for posters e.g.   -B   Print only even (TeX) pages
-c # Uncollated copies               -C # Collated copies
-d # Debugging                       -D # Resolution
-e # Maxdrift value                  -E*  Try to create EPSF
-f*  Run as filter                   -F*  Send control-D at end
                                     -G*  Shift low chars to higher pos.
-h f Add header file
-i*  Separate file per section
-j*  Download fonts partially
-k*  Print crop marks                -K*  Pull comments from inclusions
-l # Last page                       -L*  Last special papersize wins
-m*  Manual feed                     -M*  Don't make fonts
-mode s Metafont device name
-n # Maximum number of pages         -N*  No structured comments
-noomega  Disable Omega extensions
-noptex   Disable pTeX extensions
-o f Output file                     -O c Set/change paper offset
-p # First page                      -P s Load config.$s
-pp l Print only pages listed
-q*  Run quietly
-r*  Reverse order of pages          -R*  Run securely
-s*  Enclose output in save/restore  -S # Max section size in pages
-t s Paper format                    -T c Specify desired page size
-u s PS mapfile                      -U*  Disable string param trick
-v   Print version number and quit   -V*  Send downloadable PS fonts as PK
-x # Override dvi magnification      -X # Horizontal resolution
-y # Multiply by dvi magnification   -Y # Vertical resolution
-z*  Hyper PS                        -Z*  Compress bitmap fonts
    # = number   f = file   s = string  * = suffix, `0' to turn off
    c = comma-separated dimension pair (e.g., 3.2in,-32.1cm)
    l = comma-separated list of page ranges (e.g., 1-4,7-9)

Email bug reports to tex-k@mail.tug.org.

3.2.2 Option details
--------------------

Many of the parameterless options listed here can be turned off by
suffixing the option with a zero ('0'); for instance, to turn off page
reversal, use '-r0'.  Such options are marked with a trailing '*'.

'-'
     Read additional options from standard input after processing the
     command line.

'--help'
     Print a usage message and exit.

'--version'
     Print the version number and exit.

'-a*'
     Conserve memory by making three passes over the DVI file instead of
     two and only loading those characters actually used.  Generally
     only useful on machines with a very limited amount of memory, like
     some PCs.

'-A'
     Print only the odd pages.  This option uses TeX page numbers, not
     physical page numbers.

'-b NUM'
     Generate NUM copies of each page, but duplicating the page body
     rather than using the '/#copies' PostScript variable.  This can be
     useful in conjunction with a header file setting 'bop-hook' to do
     color separations or other neat tricks.

'-B'
     Print only the even pages.  This option uses TeX page numbers, not
     physical page numbers.

'-c NUM'
     Generate NUM consecutive copies of every page, i.e., the output is
     uncollated.  This merely sets the builtin PostScript variable
     '/#copies'.

'-C NUM'
     Generate NUM copies, but collated (by replicating the data in the
     PostScript file).  Slower than the '-c' option, but easier on the
     hands, and faster than resubmitting the same PostScript file
     multiple times.

'-d NUM'
     Set the debug flags, showing what Dvips (thinks it) is doing.  This
     will work unless Dvips has been compiled without the 'DEBUG' option
     (not recommended).  See Debug options, for the possible values
     of NUM.  Use '-d -1' as the first option for maximum output.

'-D NUM'
     Set both the horizontal and vertical resolution to NUM, given in
     dpi (dots per inch).  This affects the choice of bitmap fonts that
     are loaded and also the positioning of letters in resident
     PostScript fonts.  Must be between 10 and 10000.  This affects both
     the horizontal and vertical resolution.  If a high resolution
     (something greater than 400 dpi, say) is selected, the '-Z' flag
     should probably also be used.  If you are using fonts made with
     Metafont, such as Computer Modern, 'mktexpk' needs to know about
     the value for NUM that you use or Metafont will fail.  See the file
     <ftp://ftp.tug.org/tex/modes.mf> for a list of resolutions and mode
     names for most devices.

'-e NUM'
     Maximum drift in pixels of each character from its 'true'
     resolution-independent position on the page.  The default value of
     this parameter is resolution dependent (it is the number of entries
     in the list [100, 200, 300, 400, 500, 600, 800, 1000, 1200, 1600,
     2000, 2400, 2800, 3200, ...] that are less than or equal to the
     resolution in dots per inch).  Allowing individual characters to
     'drift' from their correctly rounded positions by a few pixels,
     while regaining the true position at the beginning of each new
     word, improves the spacing of letters in words.

'-E*'
     Generate an EPSF file with a tight bounding box.  This only looks
     at marks made by characters and rules, not by any included
     graphics.  In addition, it gets the glyph metrics from the TFM
     file, so characters that print outside their enclosing TFM box may
     confuse it.  In addition, the bounding box might be a bit too loose
     if the character glyph has significant left or right side bearings.
     Nonetheless, this option works well enough for creating small EPSF
     files for equations or tables or the like.  (Of course, Dvips
     output, especially when using bitmap fonts, is resolution-dependent
     and thus does not make very good EPSF files, especially if the
     images are to be scaled; use these EPSF files with care.)  For
     multiple page input files, also specify '-i' to get each page as a
     separate EPSF file; otherwise, all the pages are overlaid in the
     single output file.

'-f*'
     Run as a filter.  Read the DVI file from standard input and write
     the PostScript to standard output.  The standard input must be
     seekable, so it cannot be a pipe.  If your input must be a pipe,
     write a shell script that copies the pipe output to a temporary
     file and then points Dvips at this file.  This option also disables
     the automatic reading of the 'PRINTER' environment variable; use
     '-P$PRINTER' after the '-f' to read it anyway.  It also turns off
     the automatic sending of control-D if it was turned on with the
     '-F' option or in the configuration file; use '-F' after the '-f'
     to send it anyway.

'-F*'
     Write control-D (ASCII code 4) as the very last character of the
     PostScript file.  This is useful when Dvips is driving the printer
     directly instead of working through a spooler, as is common on
     personal systems.  On systems shared by more than one person, this
     is not recommended.

'-G*'
     Shift non-printing characters (ASCII 0-32, 127) to higher-numbered
     positions.  This was useful to work around bugs in old versions of
     Adobe's PDF reader.  It's more likely to cause problems nowadays.

'-h NAME'
     Prepend NAME as an additional header file, or, if NAME is '-',
     suppress all header files.  Any definitions in the header file get
     added to the PostScript 'userdict'.

'-i*'
     Make each section be a separate file; a "section" is a part of the
     document processed independently, most often created to avoid
     memory overflow.  The filenames are created replacing the suffix of
     the supplied output file name by a three-digit sequence number.
     This option is most often used in conjunction with the '-S' option
     which sets the maximum section length in pages; if '-i' is
     specified and '-S' is not, each page is output as a separate file.
     For instance, some phototypesetters cannot print more than ten or
     so consecutive pages before running out of steam; these options can
     be used to automatically split a book into ten-page sections, each
     to its own file.

     On the other hand, if your document uses very large fonts or very
     large included figures, Dvips might take it upon itself to split
     the output into unwanted sections, to try to avoid overflowing
     printer memory.  See Headers and memory usage, for ways to
     handle this.

'-j*'
     Download only needed characters from Type 1 fonts.  This is the
     default in the current release.  Some debugging flags trace this
     operation (see Debug options).  You can also control partial
     downloading on a per-font basis (see psfonts.map).

'-k*'
     Print crop marks.  This option increases the paper size (which
     should be specified, either with a paper size special or with the
     '-T' option) by a half inch in each dimension.  It translates each
     page by a quarter inch and draws cross-style crop marks.  It is
     mostly useful with typesetters that can set the page size
     automatically.  This works by downloading 'crop.pro'.

'-K*'
     Remove comments in included PostScript graphics, font files, and
     headers; only necessary to get around bugs in spoolers or
     PostScript post-processing programs.  Specifically, the '%%Page'
     comments, when left in, often cause difficulties.  Use of this flag
     can cause other graphics to fail, however, since the PostScript
     header macros from some software packages read portion the input
     stream line by line, searching for a particular comment.

'-l [=]NUM'
     The last page printed will be the first one numbered NUM.  Default
     is the last page in the document.  If NUM is prefixed by an equals
     sign, then it (and the argument to the '-p' option, if specified)
     is treated as a physical (absolute) page number, rather than a
     value to compare with the TeX '\count0' values stored in the DVI
     file.  Thus, using '-l =9' will end with the ninth page of the
     document, no matter what the pages are actually numbered.

'-L*'
     By default or with '-L1', the last 'papersize' special wins; with
     '-L0', the first special wins.  See papersize special.

'-m*'
     Specify manual feed, if supported by the output device.

'-mode MODE'
     Use MODE as the Metafont device name for path searching and font
     generation.  This overrides any value from configuration files.
     With the default paths, explicitly specifying the mode also makes
     the program assume the fonts are in a subdirectory named MODE.
     See TeX directory structure (kpathsea).
     If Metafont does not understand the MODE name, see
     Unable to generate fonts (kpathsea).

'-M*'
     Turns off automatic font generation ('mktexpk').  If 'mktexpk', the
     invocation is appended to a file 'missfont.log' (by default) in the
     current directory.  You can then execute the log file to create the
     missing files after fixing the problem.  If the current directory
     is not writable and the environment variable or configuration file
     value 'TEXMFOUTPUT' is set, its value is used.  Otherwise, nothing
     is written.  The name 'missfont.log' is overridden by the
     'MISSFONT_LOG' environment variable or configuration file value.

'-n NUM'
     Print at most NUM pages.  Default is 100000.

'-N*'
     Turns off generation of structured comments such as '%%Page'; this
     may be necessary on some systems that try to interpret PostScript
     comments in weird ways, or on some PostScript printers.  Old
     versions of TranScript in particular cannot handle modern
     Encapsulated PostScript.  Beware: This also disables page movement,
     etc., in PostScript viewers such as Ghostview.

'-noomega'
     Disable the use of Omega extensions when interpreting DVI files.
     By default, the additional opcodes '129' and '134' are recognized
     by Dvips as Omega or pTeX extensions and interpreted as requests to
     set 2-byte characters.

'-noptex'
     Disable the use of pTeX extensions when interpreting DVI files.  By
     default, the additional opcodes '130' and '135' are recognized by
     Dvips as Omega extensions and interpreted as requests to set 3-byte
     characters, and '255' as request to change the typesetting
     direction.

     The only drawback is that the virtual font array will (at least
     temporarily) require 65536 or more positions instead of the default
     256 positions, i.e., the memory requirements of Dvips will be
     somewhat larger.  If you find this unacceptable or encounter
     another problem with the Omega or pTeX extensions, you can switch
     off the pTeX extension by using '-noptex', or both by using
     '-noomega' (but please do send a bug report if you find such
     problems, see Bugs (kpathsea)).

'-o NAME'
     Send output to the file NAME.  If '-o' is specified without NAME
     (i.e., it is the last thing on the command line), the default is
     'FILE.ps' where the input DVI file was 'FILE.dvi'.  If '-o' isn't
     given at all, the configuration file default is used.

     If NAME is '-', output goes to standard output.  If the first
     character of NAME is '!' or '|', then the remainder will be used as
     an argument to 'popen'; thus, specifying '|lpr' as the output file
     will automatically queue the file for printing as usual.  (The
     MS-DOS version will print to the local printer device 'PRN' when
     NAME is '|lpr' and a program by that name cannot be found.)

     '-o' disables the automatic reading of the 'PRINTER' environment
     variable, and turns off the automatic sending of control-D. See the
     '-f' option for how to override this.

'-O X-OFFSET,Y-OFFSET'
     Move the origin by X-OFFSET,Y-OFFSET, a comma-separated pair of
     dimensions such as '.1in,-.3cm' (see papersize special).  The
     origin of the page is shifted from the default position (of one
     inch down, one inch to the right from the upper left corner of the
     paper) by this amount.  This is usually best specified in the
     printer-specific configuration file.

     This is useful for a printer that consistently offsets output pages
     by a certain amount.  You can use the file 'testpage.tex' to
     determine the correct value for your printer.  Be sure to do
     several runs with the same 'O' value--some printers vary widely
     from run to run.

     If your printer offsets every other page consistently, instead of
     every page, your best recourse is to use 'bop-hook' (see
     PostScript hooks).

'-p [=]NUM'
     The first page printed will be the first one numbered NUM.  Default
     is the first page in the document.  If NUM is prefixed by an equals
     sign, then it (and the argument to the '-l' option, if specified)
     is treated as a physical (absolute) page number, rather than a
     value to compare with the TeX '\count0' values stored in the DVI
     file.  Thus, using '-p =3' will start with the third page of the
     document, no matter what the pages are actually numbered.

'-pp FIRST-LAST'
     Print pages FIRST through LAST; equivalent to '-p FIRST -l LAST',
     except that multiple '-pp' options accumulate, unlike '-p' and
     '-l'.  The '-' separator can also be ':'.

'-P PRINTER'
     Read the configuration file 'config.PRINTER' ('PRINTER.cfg' on
     MS-DOS), which typically sets the output name (most likely 'o |lpr
     -PPRINTER'), resolution, Metafont mode, and perhaps other
     printer-specific defaults.  It works best to put sitewide defaults
     in the one master 'config.ps' file and only things that vary from
     printer to printer in the 'config.PRINTER' files; 'config.ps' is
     read before 'config.PRINTER'.

     A configuration file for eventual creation of Adobe PDF files is
     provided in 'config.pdf' and thus can be loaded with '-Ppdf'.  It
     will try to include Type 1 outline fonts into the PostScript file
     (see Hypertext caveats).

     If no '-P' or '-o' is given, the environment variable 'PRINTER' is
     checked.  If that variable exists, and a corresponding
     'config.PRINTER' ('PRINTER.cfg' on MS-DOS) file exists, it is read.
     See Configuration file searching.

'-q*'
     Run quietly.  Don't chatter about pages converted, etc., and report
     no warnings (only errors) to standard error.

'-r*'
     Output pages in reverse order.  By default, page 1 is output first.

'-R'
     Run securely.  '-R2' disables both shell command execution in
     '\special' (via '`', see Dynamic creation of graphics) and
     config files (via the 'E' option, see Configuration file commands)
     and opening of any absolute or '..'-relative filenames.
     '-R1', the default, forbids shell escapes but allows absolute
     filenames.  '-R0' allows both.

'-s*'
     Enclose the output in a global save/restore pair.  This causes the
     file to not be truly conformant, and is thus not recommended, but
     is useful if you are driving a deficient printer directly and thus
     don't care too much about the portability of the output to other
     environments.

'-S NUM'
     Set the maximum number of pages in each 'section'.  This option is
     most commonly used with the '-i' option; see its description above
     for more information.

'-t PAPERTYPE'
     Set the paper type to PAPERTYPE, usually defined in one of the
     configuration files, along with the appropriate PostScript code to
     select it (see Config file paper sizes).
        - You can also specify a PAPERTYPE of 'landscape', which rotates
          a document by 90 degrees.
        - To rotate a document whose paper type is not the default, you
          can use the '-t' option twice, once for the paper type, and
          once for 'landscape'.
        - In general, you should not use any '-t' option when using a
          'papersize' special, which some LaTeX packages (e.g.,
          'hyperref') insert.
        - One exception is when using a nonstandard paper size that is
          not already defined in 'config.ps'; in this case, you need to
          specify '-t unknown'.
        - Another exception is when producing multi-page files for
          further processing; use '-t nopaper' to omit any paper size
          information in the output.  (If you just have a single page
          document, you can use '-E' to get pure EPSF output.)

'-T HSIZE,VSIZE'
     Set the paper size to (HSIZE,VSIZE), a comma-separated pair of
     dimensions such as '.1in,-.3cm' (see papersize special).  It
     overrides any paper size special in the DVI file.  Be careful, as
     the paper size will stick to a predefined size if there is one
     close enough.  To disable this behavior, use '-tunknown'.

'-u PSMAPFILE'
     Set PSMAPFILE to be the file that dvips uses for looking up
     PostScript font aliases.  If PSMAPFILE begins with a '+' character,
     then the rest of the name is used as the name of the map file, and
     the map file is appended to the list of map files (instead of
     replacing the list).  In either case, if the name has no extension,
     then '.map' is added at the end.

'-U*'
     Disable a PostScript virtual memory-saving optimization that stores
     the character metric information in the same string that is used to
     store the bitmap information.  This is only necessary when driving
     the Xerox 4045 PostScript interpreter, which has a bug that puts
     garbage on the bottom of each character.  Not recommended unless
     you must drive this printer.

'-v'
     Print the dvips version number and exit.

'-V*'
     Download non-resident PostScript fonts as bitmaps.  This requires
     use of 'mtpk' or 'gsftopk' or 'pstopk' or some combination thereof
     to generate the required bitmap fonts; these programs are supplied
     with Dvips.  The bitmap must be put into 'psfonts.map' as the
     downloadable file for that font.  This is useful only for those
     fonts for which you do not have real outlines, being downloaded to
     printers that have no resident fonts, i.e., very rarely.

'-x NUM'
     Set the magnification ratio to NUM/1000.  Overrides the
     magnification specified in the DVI file.  Must be between 10 and
     100000.  It is recommended that you use standard magstep values
     (1095, 1200, 1440, 1728, 2074, 2488, 2986, and so on) to help
     reduce the total number of PK files generated.  NUM may be a real
     number, not an integer, for increased precision.

'-X NUM'
     Set the horizontal resolution in dots per inch to NUM.

'-y NUM'
     Set the magnification ratio to NUM/1000 times the magnification
     specified in the DVI file.  See '-x' above.

'-Y NUM'
     Set the vertical resolution in dots per inch to NUM.

'-z*'
     Pass 'html' hyperdvi specials through to the output for eventual
     distillation into PDF. This is not enabled by default to avoid
     including the header files unnecessarily, and use of temporary
     files in creating the output.  See Hypertext.

'-Z*'
     Compress bitmap fonts in the output file, thereby reducing the size
     of what gets downloaded.  Especially useful at high resolutions or
     when very large fonts are used.  May slow down printing, especially
     on early 68000-based PostScript printers.  Generally recommend
     today, and can be enabled in the configuration file (see
     Configuration file commands).

3.3 Environment variables
=========================

Dvips looks for many environment variables, to define search paths and
other things.  The path variables are read as needed, after all
configuration files are read, so they override values in the
configuration files.  (Except for 'TEXCONFIG', which defines where the
configuration files themselves are found.)

   See Path specifications (kpathsea), for details of interpretation
of path and other environment variables common to all Kpathsea-using
programs.  Only the environment variables specific to Dvips are
mentioned here.

'DVIPSDEBUG'
     Write the absolute path names of any configuration or map files to
     standard output, for debugging.  This isn't done by default because
     these files are read even before the banner is printed.  For
     voluminous additional debugging, set the environment variable
     'KPATHSEA_DEBUG' to '-1' (see Debugging (kpathsea)).  (If
     'KPATHSEA_DEBUG' is set to any value, it automatically turns on
     'DVIPSDEBUG'.)

'DVIPSFONTS'
     Default path to search for all fonts.  Overrides all the font path
     config file options and other environment variables (see
     Supported file formats (kpathsea)).

'DVIPSHEADERS'
     Default path to search for PostScript header files.  Overrides the
     'H' config file option (see Configuration file commands).

'DVIPSMAKEPK'
     Overrides 'mktexpk' as the name of the program to invoke to create
     missing PK fonts.  You can change the arguments passed to the
     'mktexpk' program with the 'MAKETEXPK' environment variable; see
     MakeTeX script arguments (kpathsea).

'DVIPSRC'
     Specifies the name of the startup file (see Configuration file searching)
     which is read after 'config.ps' but before any
     printer-specific configuration files.

'DVIPSSIZES'
     Last-resort sizes for scaling of unfound fonts.  Overrides the 'R'
     definition in config files (see Configuration file commands).

'PRINTER'
     Determine the default printer configuration file.  (Dvips itself
     does not use 'PRINTER' to determine the output destination in any
     way.)

'TEXCONFIG'
     Path to search for Dvips' 'config.PRINTER' configuration files,
     including the base 'config.ps'.  Using this single environment
     variable, you can override everything else.  (The printer-specific
     configuration files are called 'PRINTER.cfg' on MS-DOS, but
     'config.ps' is called by that name on all platforms.)

'TEXPICTS'
     Path to search for included graphics files.  Overrides the 'S'
     config file option (see Configuration file commands).  If not
     set, 'TEXINPUTS' is looked for.  See Supported file formats (kpathsea).

3.4 Dvips configuration files
=============================

This section describes in detail the Dvips-specific 'config.*' device
configuration files (called '*.cfg' on MS-DOS), which override the
'texmf.cnf' configuration files generic to Kpathsea which Dvips also
reads (see Config files (kpathsea)).

   For information about installing these files, including a prototype
file you can copy, see config.ps installation.

3.4.1 Configuration file searching
----------------------------------

The Dvips program loads many different configuration files, so that
parameters can be set globally across the system, on a per-device basis,
or individually by each user.

  1. Dvips first reads (if it exists) 'config.ps'; it is searched for
     along the path for Dvips configuration files, as described in
     Supported file formats (kpathsea).

  2. A user-specific startup file is loaded, so individual users can
     override any options set in the global file.  The environment
     variable 'DVIPSRC', if defined, is used as the specification of the
     startup file.  If this variable is undefined, Dvips uses a
     platform-specific default name.  On Unix Dvips looks for the
     default startup file under the name '$HOME/.dvipsrc', which is in
     the user's home directory.  On MS-DOS and MS-Windows, where users
     generally don't have their private directories, the startup file is
     called 'dvips.ini' and it is searched for along the path for Dvips
     configuration files (as described in Supported file formats (kpathsea).);
     users are expected to set this path as they see fit
     for their taste.

  3. The command line is read and parsed: if the '-PDEVICE' option is
     encountered, at that point 'config.DEVICE' is loaded.  Thus, the
     printer configuration file can override anything in the site-wide
     or user configuration file, and it can also override options in the
     command line up to the point that the '-P' option was encountered.
     (On MS-DOS, the printer configuration files are called
     'DEVICE.cfg', since DOS doesn't allow more than 3 characters after
     the dot in filenames.)

  4. If no '-P' option was specified, and also the '-o' and '-f' command
     line options were not used, Dvips checks the environment variable
     'PRINTER'.  If it exists, then 'config.$PRINTER' ('$PRINTER.cfg' on
     MS-DOS) is loaded (if it exists).

   Because the '.dvipsrc' file is read before the printer-specific
configuration files, individual users cannot override settings in the
latter.  On the other hand, the 'TEXCONFIG' path can be set to anything,
so the users can always define their own printer-specific configuration
files to be found before the system's.

   A few command-line options are treated specially, in that they are
not overridden by configuration files:

'-D'
     As well as setting the resolution, this unsets the mode, if the
     mode was previously set from a configuration file.  If
     'config.$PRINTER' is read, however, any 'D' or 'M' lines from there
     will take effect.

'-mode'
     This overrides any mode setting ('M' line) in configuration files.
     '-mode' does not affect the resolution.

'-o'
     This overrides any output setting ('o' line) in configuration
     files.

   The purpose of these special cases is to (1) minimize the chance of
having a mismatched mode and resolution (which 'mktexpk' cannot
resolve), and (2) let command-line options override config files where
possible.

3.4.2 Configuration file commands
---------------------------------

Most of the configuration file commands are similar to corresponding
command line options, but there are a few exceptions.  When they are the
same, we omit the description here.

   As with command line options, many may be turned off by suffixing the
letter with a zero ('0').

   Within a configuration file, empty lines, and lines starting with a
space, asterisk, equal sign, percent sign, or pound sign are ignored.
There is no provision for continuation lines.

'@ NAME HSIZE VSIZE'
     Define paper sizes.  See Config file paper sizes.

'a*'
     Memory conservation.  Same as '-a', see Option details.

'b #COPIES'
     Multiple copies.  Same as '-b', see Option details.

'c FILENAME'
     Include FILENAME as an additional configuration file, read
     immediately.

'D DPI'
     Output resolution.  Same as '-D', see Option details.

'e NUM'
     Max drift.  Same as '-e', see Option details.

'E COMMAND'
     Executes the command listed with 'system'(3); can be used to get
     the current date into a header file for inclusion, for instance.
     Possibly dangerous; this may be disabled, in which case a warning
     will be printed if the option is used (and warnings are not
     suppressed).

'f*'
'F'
     Run as a filter.  Same as '-f', see Option details.

'G*'
     Shift low-numbered characters; obsolete.  Same as '-G', see
     Option details.

'h HEADER'
     Prepend HEADER to output.  Same as 'h-', see Option details.

'H PATH'
     Use PATH to search for PostScript header files.  The environment
     variable 'DVIPSHEADERS' overrides this.

'i N'
     Make multiple output files.  Same as '-i -S N', see Option details.

'j*'
     Partially download Type 1 fonts.  Same as '-j', see Option details.

'K*'
     Remove comments from included PostScript files.  Same as '-K',
     see Option details.

'L*'
     If zero, the first paper size specified is effective, else the
     last.  Same as '-L', see Option details.

'm NUM'
     Declare NUM as the memory available for fonts and strings in the
     printer.  The compile-time default is 180000, but this is typically
     overridden by 'config.ps' or other configuration files.  This value
     must be accurate if memory conservation and document splitting is
     to work correctly.  To determine this value, send the following
     file to the printer:

          %! Hey, we're PostScript
          /Times-Roman findfont 30 scalefont setfont 144 432 moveto
          vmstatus exch sub 40 string cvs show pop showpage

     The number printed by this file is the total memory free; it is
     usually best to tell Dvips that the printer has slightly less
     memory, because many programs download permanent macros that can
     reduce the memory in the printer.  Some systems or printers can
     dynamically increase the memory available to a PostScript
     interpreter, in which case this file might return a ridiculously
     low number; for example, the NeXT computer and Ghostscript.  In
     these cases, a value of, say, 10 million is likely fine.

     To go all out: If NUM is zero or negative, Dvips sets the available
     memory to a very large number (the maximum integer value in C), the
     idea being that output is not to a printer and thus no splitting of
     the output is desirable.  The Dvips config file 'config.maxmem' is
     provided to do this conveniently, namely with 'dvips -Pmaxmem'.

'M MODE'
     Metafont mode.  Same as '-mode', see Option details.

'N*'
     Disable structured comments.  Beware: This also turns off
     displaying page numbers or changing to specific pagenumbers in
     PostScript viewers.  Same as '-N', see Option details.

'o NAME'
     Send output to NAME.  Same as '-o', see Option details.  In the
     file 'config.foo', a setting like this is probably appropriate:
          o |lpr -Pfoo
     The MS-DOS version will emulate spooling to 'lpr' by printing to
     the local printer device 'PRN' if it doesn't find an executable
     program by that name in the current directory or along the 'PATH'.

'O XOFF,YOFF'
     Origin offset.  Same as '-O', see Option details.

'p [+]NAME'
     Examine NAME for PostScript font aliases.  Default is
     'psfonts.map'.  This option allows you to specify different
     resident fonts that different printers may have.  If NAME starts
     with a '+' character, then the rest of the name (after any leading
     spaces) is used as an additional map file; thus, it is possible to
     have local map files pointed to by local configuration files that
     append to the global map file.  This can be used for font families.

'P PATH'
     Use PATH to search for bitmap PK font files is PATH.  The
     'PKFONTS', 'TEXPKS', 'GLYPHFONTS', and 'TEXFONTS' environment
     variables override this.  See Supported file formats (kpathsea).

'q*'
'Q'
     Run quietly.  Same as '-q', see Option details.

'r*'
     Page reversal.  Same as '-r', see Option details.

'R NUM1 NUM2 ...'
     Define the list of default resolutions for PK fonts.  If a font
     size actually used in a document is not available and cannot be
     created, Dvips will scale the font found at the closest of these
     resolutions to the requested size, using PostScript scaling.  The
     resulting output may be ugly, and thus a warning is issued.  To
     turn this last-resort scaling off, use a line with just the 'R' and
     no numbers.

     The given numbers must be sorted in increasing order; any number
     smaller than the preceding one is ignored.  This is because it is
     better to scale a font up than down; scaling down can obliterate
     small features in the character shape.

     The environment and config file values 'DVIPSSIZES' or 'TEXSIZES'
     override this configuration file setting.

     If no 'R' settings or environment variables are specified, a list
     compiled in during installation is used.  This default list is
     defined by the Makefile variable 'default_texsizes', defined in the
     file 'make/paths.make'.

's*'
     Output global save/restore.  Same as '-s', see Option details.

'S PATH'
     Use PATH to search for special illustrations (Encapsulated
     PostScript files or psfiles).  The 'TEXPICTS' and then 'TEXINPUTS'
     environment variables override this.

'T PATH'
     Use PATH to search for TFM files.  The 'TFMFONTS' and then
     'TEXFONTS' environment variables overrides this.  This path is used
     for resident fonts and fonts that can't otherwise be found.

'U*'
     Work around bug in Xerox 4045 printer.  Same as '-U', see Option details.

'V PATH'
     Use PATH to search for virtual font files.  This may be
     device-dependent if you use virtual fonts to simulate actual fonts
     on different devices.

'W [STRING]'
     If STRING is supplied, write it to standard error after reading all
     the configuration files; with no STRING, cancel any previous 'W'
     message.  This is useful in the default configuration file to
     remind users to specify a printer, for instance, or to notify users
     about special characteristics of a particular printer.

'X NUM'
     Horizontal resolution.  Same as '-X' (see Option details).

'Y NUM'
     Vertical resolution.  Same as '-Y' (see Option details).

'Z*'
     Compress bitmap fonts.  Same as '-Z' (see Option details).

'z*'
     Disables execution of system commands, like '-R' (see Option details).
     If '-R' is specified on the command line, that takes
     precedence.

4 Paper size and landscape orientation
**************************************

Most TeX documents at a particular site are designed to use the local
standard paper size (letter size in the United States, A4 elsewhere).
The Dvips program can be customized either sitewide or for a particular
printer.

   On the other hand, plenty of documents are designed for other paper
sizes.  For instance, you may want to design a document that has the
long edge of the paper horizontal.  This can be useful when typesetting
booklets, brochures, complex tables, or many other documents.  This type
of paper orientation is called "landscape" orientation (the default
orientation is called "portrait").  Alternatively, a document might be
designed for ledger or A3 paper.

   Since the intended paper size in these cases is a document design
decision, not a printing decision, such information should be given in
the TeX file and not on the Dvips command line.  For this reason, Dvips
supports a 'papersize' special.  It is hoped that this special will
become standard over time for TeX previewers and other printer drivers.

   Some LaTeX packages, e.g., 'hyperref.sty', write a 'papersize'
special into the DVI file.  In this case, you need not and should not
attempt to override it manually.

4.1 'papersize' special
=======================

The format of the 'papersize' special is

     \special{papersize=WIDTH,HEIGHT}

WIDTH is the horizontal size of the page, and HEIGHT is the vertical
size.  The dimensions supported are the same as for TeX; namely, in
(inches), cm (centimeters), mm (millimeters), pt (points), sp (scaled
points), bp (big points, the same as the default PostScript unit), pc
(picas), dd (didot points), and cc (ciceros).

   For a US letter size landscape document, the 'papersize' would be:
     \special{papersize=11in,8.5in}

An alternate specification of 'landscape':
     \special{landscape}

This is supported for backward compatibility, but it is hoped that
reventually the 'papersize' comment will dominate.

   Of course, such a '\special' only informs Dvips of the desired paper
size; you must also adjust '\hsize' and '\vsize' in your TeX document
typeset to those dimensions.

   When using the 'papersize' special, you generally should not also
specify '-t' on the command line (see Option details).  The
exception is when using a nonstandard paper size that isn't predefined;
in this case, use '-t unknown'.

   The 'papersize' special must occur somewhere on the first page of the
document.  Some packages, notably 'hyperref', insert this special.

   By default, if a DVI file contains multiple 'papersize' specials, the
last one wins; this is also the behavior of the 'dvipdfmx' driver.  If
the '-L0' command line option or 'L0' config file command is specified,
the first special wins--this was the behavior of Dvips prior to the 2017
release.

4.2 Configuration file paper size command
=========================================

The '@' command in a configuration file sets the paper size defaults and
options.  The first '@' command defines the default paper size.  It has
three possible parameters:

     @ [NAME [HSIZE VSIZE]]

   If '@' is specified on a line by itself, with no parameters, it
instructs Dvips to discard all previous paper size information (possibly
from another configuration file).

   If three parameters are given, with the first parameter being a name
and the second and third being a dimension (as in '8.5in' or '3.2cc',
just like in the 'papersize' special), then the option is interpreted as
starting a new paper size description, where NAME is the name and HSIZE
and VSIZE define the horizontal and vertical size of the sheet of paper,
respectively.  For example:

     @ letterSize 8.5in 11in

   If both HSIZE and VSIZE are zero (you must still specify units!) then
any page size will match.  If the '@' character is immediately followed
by a '+' sign, then the remainder of the line (after skipping any
leading blanks) is treated as PostScript code to send to the printer,
presumably to select that particular paper size:

     @ letter 8.5in 11in
     @+ %%BeginPaperSize: Letter
     @+ letter
     @+ %%EndPaperSize

   After all that, if the first character of the line is an exclamation
point, then the line is put in the initial comments section of the final
output file; else, it is put in the setup section of the output file.
For example:

     @ legal 8.5in 14in
     @+ ! %%DocumentPaperSizes: Legal
     @+ %%BeginPaperSize: Legal
     @+ legal
     @+ %%EndPaperSize

   When Dvips has a paper format name given on the command line, it
looks for a match by the NAME; when it has a 'papersize' special, it
looks for a match by dimensions.  The best match found (from the paper
size information in the configuration file) is used.  The dimensions
must match within 5bp.

   If nothing matches, a warning is printed and the first paper size
with zero dimensions is used; this should be the 'unknown' paper size
definition mentioned below, resulting in the actual dimensions being
used.

   Landscape mode for all paper sizes is automatically supported.

   If your printer has a command to set a special paper size, then give
dimensions of '0in 0in'; the PostScript code that sets the paper size
can refer to the dimensions the user requested as 'hsize' and 'vsize';
these will be macros defined in the PostScript that return the requested
size in default PostScript units.  Also, some printers want
'BeginPaperSize' comments and paper size setting commands; others (such
as the NeXT) want 'PaperSize' comments and they will handle setting the
paper size.  So paper size entries should typically specify both.

   When using a paper size that is not already defined in 'config.ps',
you probably want to say '-t unknown' on the command line; the 'unknown'
paper size definition in 'config.ps' has the requisite PostScript
incantation to set the PostScript page size, as just described.

   If you want no paper size information in the output at all, use
'-t nopaper'.  This is useful with multi-page output that will be
processed further.  If you just have a single page document, you can use
'-E' to get pure EPSF output.

   The Perl 5 script 'contrib/configs/mkdvipspapers' in the distribution
directory may help in determining appropriate paper size definitions.

   Notwithstanding the above, the default 'letter' and 'a4' paper size
definitions in 'config.ps' execute the 'setpagedevice' operator if it
exists (it was defined in PostScript Level 2), or the 'letter' or 'a4'
operator if they exist (they are nonstandard and thus perhaps cause
failures on certain (unknown) printers).  Not executing any page size
definition at all confuses PostScript conversion programs such as
'ps2pdf', so we want to execute one if we can.

   The 'letterSize' and 'A4Size' paper size definitions are now synonyms
for 'letter' and 'a4'.

4.3 Paper trays
===============

Some printers, such as the Hewlett-Packard HP4si, have multiple paper
trays.  You can set up Dvips to take advantage of this using the
'bop-hook' PostScript variable (see PostScript hooks).

   For example, suppose you have an alternate tray stocked with
letterhead paper; the usual tray has the usual paper.  You have a
document where you want the first page printed on letterhead, and the
remaining pages on the usual paper.  You can create a header file, say
'firstletterhead.PS', with the following (PostScript) code ('bop-hook'
is passed the current physical page number, which starts at zero):

     /bop-hook { dup 0 eq { ALTERNATETRAY } { NORMALTRAY } ifelse } def

where ALTERNATETRAY and NORMALTRAY are the appropriate commands to
select the paper trays.  On the 4SI, ALTERNATETRAY is 'statusdict begin
1 setpapertray end' and NORMALTRAY is 'statusdict begin 0 setpapertray
end'.

   Then, include the file with either
   * the '-h' command-line option (see Option details); or

   * the 'h' config file option (see Configuration file commands);
     or

   * '\special{header=FILE}' in your TeX document (see Including headers from TeX).

5 Interaction with PostScript
*****************************

Dvips supports inclusion of PostScript figure files (e.g., Encapsulated
PostScript), downloading other header files (e.g., fonts), including
literal PostScript code, and hypertext.

5.1 PostScript figures
======================

Scaling and including PostScript graphics is a breeze--if the PostScript
file is correctly formed.  Even if it is not, however, the file can
usually be accommodated with just a little more work.

5.1.1 The bounding box comment
------------------------------

The most important feature of a good PostScript file from the standpoint
of including it in another document is an accurate bounding box comment.
Every well-formed PostScript file has a comment describing where on the
page the graphic is located, and how big that graphic is.

   This information is given as the lower left and upper right corners
of the box just enclosing the graphic, and is thus referred to as the
"bounding box".  These coordinates are given in the default PostScript
units (there are precisely 72 PostScript units to the inch, like TeX big
points) with respect to the lower left corner of the sheet of paper.

   To see if a PostScript file has a bounding box comment, just look at
the first few lines of the file.  PostScript files are standard ASCII,
so you can use any text editor to do this.  If within the first few
dozen lines there is a line like

     %%BoundingBox: 25 50 400 300

(with any reasonable numbers), chances are very good that the file is
Encapsulated PostScript and will work easily with Dvips.  If the file
contains instead a line like

     %%BoundingBox: (atend)

the file is still probably Encapsulated PostScript, but the bounding box
is given at the end of the file.  Dvips needs it at the beginning.  You
can move it with that same text editor, or a simple script.  (The
bounding box is given in this way when the program that generated the
PostScript couldn't know the size in advance, or was too lazy to compute
it.)

   If the document lacks a '%%BoundingBox:' altogether, you can
determine one in a couple of ways.  One is to use the 'bbfig' program
distributed with Dvips in the 'contrib' directory.  This can usually
find the correct bounding box automatically; it works best with
Ghostscript.

   If the comment looks like this:
     %%BoundingBox: 0 0 612 792

the graphic claims to take up an entire sheet of paper.  This is usually
a symptom of a bug in the program that generated it.

   The other is to do it yourself: print the file.  Now, take a ruler,
and make the following measurements (in PostScript units, so measure in
inches and multiply by 72): From the left edge of the paper to the
leftmost mark on the paper is LLX, the first number.  From the bottom
edge of the paper to the bottommost mark on the paper is LLY, the second
number.  From the left edge of the paper to the rightmost mark on the
paper is URX, the third number.  The fourth and final number, URY, is
the distance from the bottom of the page to the uppermost mark on the
paper.

   Once you have the numbers, add a comment of the following form as the
second line of the document.  (The first line should already be a line
starting with the two characters '%!'; if it is not, the file probably
isn't PostScript.)

     %%BoundingBox: LLX LLY URX URY

Or, if you don't want to modify the file, you can simply write these
numbers down in a convenient place and give them in your TeX document
when you import the graphic, as described in the next section.

   If the document does not have such a bounding box, or if the bounding
box is given at the end of the document, or the bounding box is wrong,
please complain to the authors of the software package that generated
the file.

5.1.2 The \includegraphics macro for LaTeX
------------------------------------------

Once the figure file has a bounding box comment (see the previous
section) you are ready to import the graphic into a LaTeX document.  For
LaTeX 2e, you can use the epsf, graphics or graphicx packages, but the
last is recommended--it has the most flexible syntax, and is briefly
described here.  Further information can be found in 'grfguide' or
'epslatex', which should be included in your LaTeX distribution in DVI,
PDF, or other formats.  (If you are still using LaTeX 2.09, use
epsf.sty).

   Just put the following command into your preamble:

     \usepackage[dvips]{graphicx}

   Depending on your system, a suitable driver setup may already be
present, so that LaTeX automatically produces DVI files suitable for
Dvips.  In this case you can leave out the '[dvips]' parameter.

   Now, at the point you want to include a file 'foo.eps', enter a line
such as:

     \includegraphics{foo.eps}

   However, it is usually best to omit the file extension and only use

     \includegraphics{foo}

because then you can process the same LaTeX file with different TeX
engines or DVI converters if you also provide suitable graphics files
for them, e.g., 'foo.pdf' or 'foo.png'.

   The \includegraphics command has many options, specified in
'key=value' syntax, to allow you to resize, rotate or trim the included
graphic--see 'grfguide' or 'epslatex'.  If your file does not have a
bounding box comment, you can supply the numbers as determined in the
previous section, in the same order they would have been in a normal
bounding box comment:

     \includegraphics[bb=100 100 500 500]{foo.ps}

Now, save your changes and run LaTeX and Dvips; the output should have
your graphic positioned at precisely the point you indicated, occupying
the proper amount of space.

   PostScript graphics have their origin in the lower left corner.
Therefore, in TeX, a graphic will occupy a box that extends far above
the line where it is put in, but has depth zero below it.  Combining
'\includegraphics' with '\parbox' commands or minipages can sometimes be
confusing when this is not taken into account.

5.1.3 Using the EPSF macros
---------------------------

If you are using LaTeX 2e, use the 'graphics' or 'graphicx' package.
See \includegraphics.

   If you are using plain TeX or LaTeX 2.09, you need 'epsf.tex' (for
plain TeX) and 'epsf.sty' (for LaTeX).  For plain TeX, add a line like
this near the top of your input file:

     \input epsf

If you are using LaTeX 2.09, add the 'epsf' style option, as in:

     \documentstyle[12pt,epsf]{article}

In any case, the above only needs to be done once, no matter how many
figures you plan to include.

   Now, at the point you want to include a file, enter a line such as:

     \epsffile{foo.eps}

   If you are using LaTeX, you may need to add '\leavevmode' immediately
before the '\epsffile' command to get certain environments to work
correctly.  If your file does not have a bounding box comment, you can
supply the numbers as determined in the previous section, in the same
order they would have been in a normal bounding box comment:

     \epsffile[100 100 500 500]{foo.ps}

Now, save your changes and run TeX and Dvips; the output should have
your graphic positioned at precisely the point you indicated, occupying
the proper amount of space.

   The '\epsffile' macro typesets the figure as a TeX '\vbox' at the
point of the page that the command is executed.  By default, the graphic
will have its 'natural' width (namely, the width of its bounding box).
The TeX box will have depth zero and its natural height.  By default,
the graphic will be scaled by any DVI magnification in effect, just as
is everything else in your document.  See the next section for more
information on scaling.

   If you want TeX to report the size of the figure as a message on your
terminal when it processes each figure, give the command:

     \epsfverbosetrue

5.1.3.1 EPSF scaling
....................

Usually, you will want to scale an EPSF figure to some size appropriate
for your document, since its natural size is determined by the creator
of the EPS file.

   The best way to do this is to assign the desired size to the TeX
'\epsfxsize' or '\epsfysize' variables, whichever is more convenient for
you.  That is, put

     \epsfxsize=DIMEN

right before the call to '\epsffile'.  Then the width of the TeX box
will be DIMEN and its height will be scaled proportionately.  Similarly,
you can set the vertical size with

     \epsfysize=DIMEN

in which case the height will be set and the width scaled
proportionally.

   If you set both, both will be honored, but the aspect ratio of the
included graphic may necessarily be distorted, i.e., its contents
stretched in one direction or the other.

   You can resize graphics in a more general way by redefining the
'\epsfsize' macro.  '\epsffile' calls this with two parameters: the
natural horizontal and vertical sizes of the PostScript graphic.
'\epsfsize' must expand to the desired horizontal size, that is, the
width of the '\vbox'.  Schematically:

     \def\epsfsize#1#2{BODY}

   Some useful definitions of BODY:

'\epsfxsize'
     This definition (the default) enables the default features listed
     above, by setting '\epsfxsize' to the same value it had before the
     macro was called.

'#1'
     Force the natural size by returning the first parameter (the
     original width).

'0pt'
     A special case, equivalent to '#1'.

'0.5#1'
     Scale to half the natural size.

'\hsize'
     Scale to the current '\hsize'.  (In LaTeX, use '\textwidth' instead
     of '\hsize'.)

'\ifnum#1>\hsize\hsize\else#1\fi'
     If the natural width is greater than the current '\hsize', scale to
     '\hsize', otherwise use the natural width.

   For compatibility with other PostScript drivers, it is possible to
turn off the default scaling of included figures by the DVI
magnification with the following TeX command:

     \special{! /magscale false def}

Use of this command is not recommended because it will make the
'\epsffile' graphics the "wrong" size if global magnification is being
used, and it will cause any PostScript graphics to appear improperly
scaled and out of position if a DVI to DVI program is used to scale or
otherwise modify the document.

   DVI magnification is not applied to any output from code you write in
'bop-hook' or its ilk (see PostScript hooks),

5.1.3.2 EPSF clipping
.....................

By default, clipping is disabled for included EPSF images.  This is
because clipping to the bounding box dimensions often cuts off a small
portion of the figure, due to slightly inaccurate bounding box
arguments.  The problem might be subtle; lines around the boundary of
the image might be half their intended width, or the tops or bottoms of
some text annotations might be sliced off.  If you want to turn clipping
on, just use the command

     \epsfclipon

and to turn clipping back off, use

     \epsfclipoff

5.1.4 'psfile' special
----------------------

The basic special for file inclusion is as follows:

     \special{psfile=FILENAME.ps [KEY=VALUE] ... }

This downloads the PostScript file 'FILENAME.ps' such that the current
point will be the origin of the PostScript coordinate system.  The
optional KEY=VALUE assignments allow you to specify transformations on
the PostScript.

   The possible KEYs are:

'hoffset'
     The horizontal offset (default 0).

'voffset'
     The vertical offset (default 0).

'hsize'
     The horizontal clipping size (default 612).

'vsize'
     The vertical clipping size (default 792).

'hscale'
     The horizontal scaling factor, as a percentage (default 100).

'vscale'
     The vertical scaling factor, as a percentage (default 100).

'angle'
     The rotation, in degrees (default 0).

'clip'
     Enable clipping to the bounding box (default disabled).

'llx, lly, urx, ury'
     Bounding box of the included image, just as in a '%%BoundingBox'
     comment.  Values are in big points, and may be fractional.

'rhi, rwi'
     Desired width and height of the resulting figure in the output, in
     tenths of big points (720 to the inch); may be fractional.

     If both 'rwi' and 'rhi' are nonzero, the picture is scaled,
     possibly losing aspect ratio.  If only one of 'rwi' and 'rhi' is
     nonzero, the picture is scaled, preserving aspect ratio.

   The offsets and sizes are given in PostScript units (big points).
Thus, for example:

     \special{psfile=foo.ps hoffset=72 hscale=90 vscale=90}

will shift the graphics produced by file 'foo.ps' right by one inch and
will draw it at 0.9 times normal size.  Offsets are given relative to
the point of the special command, and are unaffected by scaling or
rotation.  Rotation is counterclockwise about the origin.  The order of
operations is to rotate the figure, scale it, then offset it.

   For compatibility with older PostScript drivers, it is possible to
change the units that 'hscale' and 'vscale' are given in.  This can be
done by redefining '@scaleunit' in 'SDict' by a TeX command such as

     \special{! /@scaleunit 1 def}

The '@scaleunit' variable, which is by default 100, is what 'hscale' and
'vscale' are divided by to yield an absolute scale factor.

5.1.5 Dynamic creation of PostScript graphics files
---------------------------------------------------

PostScript is an excellent page description language--but it does tend
to be rather verbose.  Compressing PostScript graphics files can reduce
them by factor of five or more.  For this reason, if the name of an
included PostScript file ends with '.Z' or '.gz', Dvips automatically
runs 'gzip -d'.  For example:

     \epsffile[72 72 540 720]{foo.ps.gz}

Since the results of such a command are not accessible to TeX, if you
use this facility with the 'epsf' macros, you need to supply the
bounding box parameter yourself, as shown.

   More generally, if the filename parameter to one of the graphics
inclusion techniques starts with a left quote ('`'), the parameter is
instead interpreted as a command to execute that will send the actual
file to standard output.  For example:

     \special{psfile="`gnuplot foo"}

to include the file 'foo'.  Of course, the command to be executed can be
anything, including using a file conversion utility such as 'tek2ps' or
whatever is appropriate.  This feature can be disabled with the '-R'
command-line option or 'R' configuration option.

5.1.6 Fonts in figures
----------------------

You can use any font available to TeX and Dvips within a graphics file
by putting a '%*Font:' line in the leading commentary of the file.
Schematically, this looks like:

     %*Font: TFMNAME SCALEDBP DESIGNBP HEX-START:HEX-BITSTRING

   Here is the meaning of each of these elements:

TFMNAME
     The TeX TFM filename, e.g., 'cmr10'.  You can give the same TFMNAME
     on more than one '%*Font' line; this is useful when the number of
     characters from the font used needs a longer HEX-BITSTRING (see
     item below) than conveniently fits on one line.

SCALEDBP
     The size at which you are using the font, in PostScript points (TeX
     big points).  72bp = 72.27pt = 1in.

DESIGNBP
     The designsize of the font, again in PostScript points.  This
     should match the value in the TFM file TFMNAME.  Thus, for 'cmr10',
     it should be '9.96265'.

HEX-START
     The character code of the first character used from the font,
     specified as two ASCII hexadecimal characters, e.g., '4b' or '4B'
     for 'K'.

HEX-BITSTRING
     An arbitrary number of ASCII hexadecimal digits specifying which
     characters following (and including) HEX-START are used.  This is
     treated as a bitmap.  For example, if your figure used the single
     letter 'K', you would use '4b:8' for HEX-START and HEX-BITSTRING.
     If it used 'KLMNP', you would use '4b:f4'.

   MetaPost's output figures contain lines like this for bitmap fonts
used in a MetaPost label (see MetaPost (web2c)).

5.2 PostScript header files
===========================

"Header files" are bits of PostScript included in the output file;
generally they provide support for special features, rather than
producing any printed output themselves.  You can explicitly request
downloading header files if necessary for some figure, or to achieve
some special effect.

   Dvips includes some headers on its own initiative, to implement
features such as PostScript font reencoding, bitmap font downloading,
handling of '\special''s, and so on.  These standard headers are the
'.pro' files (for "prologue") in the installation directory
'$(psheaderdir)'; they are created from the '.lpro' ("long prologue")
files in the distribution by stripping comments, squeezing blank lines,
etc., for maximum efficiency.  If you want to peruse one of the standard
header files, read the '.lpro' version.

   The PostScript dictionary stack will be at the 'userdict' level when
header files are included.

5.2.1 Including headers from TeX
--------------------------------

In order to get a particular graphic file to work, a certain font or
header file might need to be sent first.  The Dvips program provides
support for this with the 'header' '\special'.  For instance, to ensure
that 'foo.ps' gets downloaded:

     \special{header=foo.ps}

   As another example, if you have some PostScript code that uses a
PostScript font not built into your printer, you must download it to the
printer.  If the font isn't used elsewhere in the document, Dvips can't
know you've used it, so you must include it in the same way, as in:

     \special{header=putr.pfa}

to include the font definition file for Adobe Utopia Roman.

   The 'header' also special allows for specifying some additional code
that should be inserted into the PostScript document before and after
the file itself, as follows:

     \special{header={foo.ps} pre={pre code} post={post code}}

   This will insert 'pre code' just before 'foo.ps' and 'post code' just
after.  It is required to use the (balanced) braces in _all_ of the
arguments, including the 'header', when using this extended syntax.

   This allows, for instance, dynamic headers, where some of the content
depends on settings from the user in (La)TeX.  Another application is
the inclusion of graphics inside the PostScript header, so that they can
be reused throughout the document, as with logs.  That avoids including
the same graphic several times.  This is implemented in the
'graphics/graphicx-psmin' package.

   This extended syntax has one additional feature.  When Dvips finds
the extended syntax, it will also look in the installed 'tex/' tree(s)
for the header file ('foo.ps' in our example), and not only in the
current directory and dvips tree as the original syntax does.  This is
because common graphics may well come with packages which are installed
in the 'tex/' tree.

5.2.2 Including headers from the command line
---------------------------------------------

You can include headers when you run Dvips, as well as from your
document (see the previous section).  To do this, run Dvips with the
option '-P HEADER'; this will read the file 'config.HEADER', which in
turn can specify a header file to be downloaded with the 'h' option.
See Configuration file commands.  These files are called
'HEADER.cfg' on MS-DOS.

   You can arrange for the same file to serve as a '-P' config file and
the downloadable header file, by starting the lines of PostScript code
with a space, leaving only the 'h' line and any comments starting in the
first column.  As an example, see 'contrib/volker/config.*'
('contrib/volker/*.cfg' on MS-DOS). (These files also perform useful
functions: controlling duplex/simplex mode on duplex printers, and
setting various screen frequencies; 'contrib/volker/README' explains
further.)

5.2.3 Headers and memory usage
------------------------------

Dvips tries to avoid overflowing the printer's memory by splitting the
output files into "sections" (see the '-i' option in Option details).
Therefore, for all header files, Dvips debits the printer
VM budget by some value.  If the header file has, in its leading
commentary a line of the form

     %%VMusage: MIN MAX

then MAX is used.  If there is no '%%VMusage' line, then the size (in
bytes) of the header file is used as an approximation.  If you want a
file to be ignored in the sectioning calculations, use '%%VMusage: 0 0'.

   Illustrations (figure files) are also checked for '%%VMusage' line.

   Therefore, if your document uses very large fonts or very large
included figures, Dvips might take it upon itself to split the output
into unwanted sections.  If this causes problems, the simplest solution
is to use 'dvips -Pmaxmem', which reads the Dvips file 'config.maxmem',
which sets Dvips's idea of the memory available to a very large number.
(See the 'm' item in Configuration file commands.)

5.3 Literal PostScript
======================

You can include literal PostScript code in your document in several
ways.

5.3.1 '"' special: Literal PostScript
-------------------------------------

For simple graphics, or just for experimentation, literal PostScript
code can be included.  Simply use a '\special' beginning with a double
quote character '"'; there is no matching closing '"'.

   For instance, the following (simple) graphic:

   [ picture of a grey triangle ]

was created by typing:

     \vbox to 100bp{\vss % a bp is the same as a PostScript unit
       \special{" newpath 0 0 moveto 100 100 lineto 394 0 lineto
       closepath gsave 0.8 setgray fill grestore stroke}}

   You are responsible for leaving space for such literal graphics, as
with the '\vbox' above.

5.3.2 'ps' special
------------------

Generally, Dvips encloses specials in a PostScript save/restore pair,
guaranteeing that the special will have no effect on the rest of the
document.  The 'ps' special, however, allows you to insert literal
PostScript instructions without this protective shield; you should
understand what you're doing (and you shouldn't change the PostScript
graphics state unless you are willing to take the consequences).  This
command can take many forms because it has had a torturous history; any
of the following will work:

     \special{ps:TEXT}
     \special{ps::TEXT}
     \special{ps::[begin]TEXT}
     \special{ps::[end]TEXT}
     \special{ps::[nobreak]TEXT}

(with longer forms taking precedence over shorter forms, when they are
present).  'ps::' and 'ps::[end]' do no positioning, so they can be used
to continue PostScript literals started with 'ps:' or 'ps::[begin]'.

   Literal PostScript instructions after 'ps::[nobreak]' are _not_
broken into lines.  This feature may be used to include PostScript
comments, for example.

   In addition, the variant

     \special{ps: plotfile FILENAME}

inserts the contents of FILENAME verbatim into the output (except for
omitting lines that begin with %).  An example of the proper use of
literal specials can be found in the file 'rotate.tex', which makes it
easy to typeset text turned in multiples of 90 degrees.

5.3.3 Literal headers: '!' '\special'
-------------------------------------

You can download literal PostScript header code in your TeX document,
for use with (for example) literal graphics code that you include later.
The text of a '\special' beginning with an '!' is copied into the output
file.  A dictionary 'SDict' will be current when this code is executed;
Dvips arranges for 'SDict' to be first on the dictionary stack when any
PostScript graphic is included, whether literally (the '"' special) or
through macros (e.g., 'epsf.tex').

   For example:

     \special{! /reset { 0 0 moveto} def}

5.3.4 PostScript hooks
----------------------

Besides including literal PostScript at a particular place in your
document (as described in the previous section), you can also arrange to
execute arbitrary PostScript code at particular times while the
PostScript is printing.

   If any of the PostScript names 'bop-hook', 'eop-hook', 'start-hook',
or 'end-hook' are defined in 'userdict', they will be executed at the
beginning of a page, end of a page, start of the document, and end of a
document, respectively.

   When these macros are executed, the default PostScript coordinate
system and origin is in effect.  Such macros can be defined in headers
added by the '-h' option or the 'header=' special, and might be useful
for writing, for instance, 'DRAFT' across the entire page, or, with the
aid of a shell script, dating the document.  These macros are executed
outside of the save/restore context of the individual pages, so it is
possible for them to accumulate information, but if a document must be
divided into sections because of memory constraints, such added
information will be lost across section breaks.

   The single argument to 'bop-hook' is the physical page number; the
first page gets zero, the second one, etc.  'bop-hook' must leave this
number on the stack.  None of the other hooks are passed arguments.

   As an example of what can be done, the following special will write a
light grey 'DRAFT' across each page in the document:

     \special{!userdict begin /bop-hook{gsave 200 30 translate
     65 rotate /Times-Roman findfont 216 scalefont setfont
     0 0 moveto 0.7 setgray (DRAFT) show grestore}def end}

   Using 'bop-hook' or 'eop-hook' to preserve information across pages
breaks compliance with the Adobe document structuring conventions, so if
you use any such tricks, you may also want to use the '-N' option to
turn off structured comments (such as '%%Page').  Otherwise, programs
that read your file will assume its pages are independent.

5.3.5 Literal examples
----------------------

To finish off this section, the following examples of literal PostScript
are presented without explanation:

     \def\rotninety{\special{ps:currentpoint currentpoint translate 90
     rotate neg exch neg exch translate}}\font\huge=cmbx10 at 14.4truept
     \setbox0=\hbox to0pt{\huge A\hss}\vskip16truept\centerline{\copy0
     \special{ps:gsave}\rotninety\copy0\rotninety\copy0\rotninety
     \box0\special{ps:grestore}}\vskip16truept

   [ There are 4 'A' characters, each rotated 90 degrees about a common
center point ]

     \vbox to 2truein{\special{ps:gsave 0.3 setgray}\hrule height 2in
     width\hsize\vskip-2in\special{ps:grestore}\font\big=cminch\big
     \vss\special{ps:gsave 1 setgray}\vbox to 0pt{\vskip2pt
     \line{\hss\hskip4pt NEAT\hss}\vss}\special{ps:0 setgray}%
     \hbox{\raise2pt\line{\hss NEAT\hss}\special{ps:grestore}}\vss}

   [ There is a big gray box with the word 'NEAT' inside in big letters
]

   Some caveats are in order, however.  Make sure that each 'gsave' is
matched with a 'grestore' on the same page.  Do not use 'save' and
'restore'; they can interact with the PostScript generated by Dvips if
care is not taken.  Try to understand what the above macros are doing
before writing your own.  The '\rotninety' macro especially has a useful
trick that appears again and again.

5.4 HyperTeXt
=============

Dvips has support for producing hypertext PostScript documents.  If you
specify the '-z' option, the 'html:' specials described below will be
converted into 'pdfmark' PostScript operators to specify links.  Without
'-z', 'html:' specials are ignored.

   The resulting PostScript can then be processed by a distiller program
to make a PDF file.  (It can still be handled by ordinary PostScript
interpreters as well.)  Various versions of both PC and Unix distillers
are supported; Ghostscript includes limited distiller support (see
Ghostscript installation).

   Macros you can use in your TeX document to insert the specials in the
first place are available from 'CTAN:/support/hypertex'.  For CTAN info,
see unixtex.ftp (kpathsea).

   This hypertext support (and original form of the documentation) was
written by Mark Doyle and Tanmoy Bhattacharya as the 'dvihps' program.
You can retrieve their software and additional documentation via the
CTAN reference above.

5.4.1 Hypertext caveats
-----------------------

If you intend to go all the way to PDF, you may want to use the standard
35 PostScript fonts exclusively, since other fonts are embedded as
bitmaps by default.  The Adobe PDF readers are extremely slow when
dealing with bitmap fonts and the results look terrible on the screen.
Printouts will probably look fine, but may not take full advantage of a
high-resolution printer.  Alternatively, you can have your fonts
embedded as Type 1 scalable outlines.  The resulting PostScript files
may be larger, but can be effectively rasterized at any resolution.
They can also be converted to PDF files that can be used effectively at
any screen or printer resolution.

   To get the TeX fonts embedded in the PostScript file as Type 1 fonts,
add '-Ppdf' to the dvips command line switches.  The printout for a run
should look something like this:

      dvips report -Ppdf -o report.ps
      This is dvips(k) 5.86 Copyright 1999 Radical Eye Software (www.radicaleye.com)
      ' TeX output 2001.06.15:0837' -> report.ps
      <tex.pro><alt-rule.pro><texc.pro><texps.pro><special.pro>.
      <cmbx9.pfb><cmsy6.pfb><cmsy7.pfb><cmr5.pfb><cmex10.pfb><cmr9.pfb>
      <cmmi7.pfb><cmsy10.pfb><cmmib10.pfb><cmmi10.pfb><cmti10.pfb>
      <cmr7.pfb><cmbx10.pfb><cmr10.pfb><cmti9.pfb><cmr12.pfb><cmbx12.pfb>
      [1] [2<mean1.ps>] [3<bounce1-00.ps>] [4]

   An entry like "<cmr10.pfb>" indicates success: dvips found the
Computer Modern Roman 10 point font in a PostScript Font Binary file,
translated it to an ASCII encoding, and embedded it.  You can confirm
this by examining the PostScript output file, looking for the section
starting '%%BeginFont: CMR10' followed by an entry '/FontType 1 def'.

   The '-Ppdf' option requires that the relevant outline ('.pfa' or
'.pfb') files be installed (see Font concepts).  For example, the
'cmr10' file might be in
'/usr/share/texmf/fonts/type1/bluesky/cm/cmr10.pfb'.  Your TeX
distribution may make those fonts available in a separate optional
package (e.g., 'tetex-extra' in Debian).  Failing that, commercial
versions of the Computer Modern fonts are available from Blue Sky;
public domain versions - in particular, the lm fonts, and the cm-super
fonts, are available from CTAN sites (for CTAN info, see
unixtex.ftp (kpathsea)).

   You can convert a PostScript file to PDF using 'distill', which comes
with Adobe Acrobat, or 'ps2pdf', which comes with Ghostscript.  The
'ps2pdf' that comes with 'Ghostscript' version 6.0 or earlier will not
embed Type 1 fonts.  Current recommendations are GNU Ghostscript 6.51 or
Aladdin Ghostscript 7.0.  You can check the fonts in a PDF file with
Acrobat Reader by selecting the menu entries 'File|Document Info|Fonts'.

   Also, the Adobe distillers prior to 2.1 drop trailing space
characters (character code 32) from strings.  Unfortunately, the
PostScript fonts use this character code for characters other than space
(notably the Greek letter psi in the 'Symbol' font), and so these
characters are dropped.  This bug is fixed in version 2.1.

   If you can't upgrade, one workaround is to change all the trailing
blanks in strings to a character code that isn't in the font.  This
works because the default behavior is to substitute a blank for a
missing character, i.e., the distiller is fooled into substituting the
right character.  For instance, with the Blue Sky fonts, you can
globally replace ' )' with '\200)' (with 'sed', for example) and get the
desired result.  With the public domain fonts, you will probably have to
use a character code in the range 128 to 191 since these fonts duplicate
the first 32 characters starting at 192 to avoid MS-DOS problems.

   For more information on the use of TeX to produce PDF files, see the
article "Creating quality Adobe PDF files from TeX with DVIPS" by
Kendall Whitehouse of Adobe.  Adobe seems not to offer the article any
more, but copies are available elsewhere:
     <http://www.math.hawaii.edu/~ralph/MathOnWeb/TeXPDF.html>
     <http://www.utdallas.edu/~cantrell/online/543e.html>

   You may also want to check "Notes on converting (La)TeX documents to
robust PDF using Rokicki's dvips and Acrobat Distiller" by Timothy P.
Van Zandt:
<http://www.emrg.com/texpdf.htmlhttp://zandtwerk.insead.fr/tex2pdf.html>.

5.4.2 Hypertext specials
------------------------

Current support for the World Wide Web in the TeX system does not
involve modifying TeX itself.  We need only define some specials; Arthur
Smith (<apsmith@aps.org>), Tanmoy Bhattacharya, and Paul Ginsparg
originally proposed and implemented the following:
     html:<a href="XURL">
     html:<a name="NAME">
     html:</a>
     html:<img src="XURL">
     html:<base href="XURL">

   Like all TeX '\special''s, these produce no visible output, and are
uninterpreted by TeX itself.  They are instructions to DVI processors
only.

   Here, XURL is a standard WWW uniform resource locator (URL), possibly
extended with a '#TYPE.STRING' construct, where TYPE is 'page',
'section', 'equation', 'reference' (for bibliographic references),
'figure', 'table', etc.  For example,
     \special{html:<a href="http://www.maths.tcd.ie/~tim/ch1.dvi#equation.1.1">}
is a link to equation (1.1) in an example document by Tim Murphy.

   See the URL
<http://www.w3.org/hypertext/WWW/Addressing/Addressing.html> for a
precise description of base URL's.

   Descriptions of the '\special''s:
'href'
     Creates links in your TeX document.  For example:
          \special{html:<a href="http://www.tug.org/">}\TeX\ Users
          Group\special{html:</a>}
     The user will be able to click on the text 'TeX Users Group' while
     running Xdvi and get to the TUG home page.  (By the way, this is
     for illustration.  In practice, you most likely want to use macros
     to insert the '\special' commands; reference above.)

'name'
     Defines URL targets in your TeX documents, so links can be
     resolved.  For example:
          \special{html:<a name="paradise">}Paradise\special{html:</a>}
          is exactly where you are right now.
     This will resolve an 'href="#paradise"'.  You'll also have to
     change the catcode of '#', etc.  It's usually easiest to use
     existing macro packages which take care of all the details, such as
     'hyperref' for LaTeX.  The HyperTeX FAQ
     (http://arxiv.org/hypertex/) has more information.

'img'
     Links to an arbitrary external file.  Interactively, a viewer is
     spawned to read the file according to the file extension and your
     'mailcap' file (see the Xdvi documentation).

'base'
     Defines a base URL that is prepended to all the 'name' targets.
     Typically unnecessary, as the name of the DVI file being read is
     used by default.

   The 'img' and 'base' tags are not yet implemented in Dvips or the
NeXTSTEP DVI viewer.

6 PostScript fonts
******************

Dvips supports the use of PostScript fonts in TeX documents.  To use a
PostScript font conveniently, you need to prepare a corresponding
virtual font; the program Afm2tfm, supplied with Dvips, helps with that.

   All the necessary support for the standard 35 PostScript fonts
('AvantGarde-Book' through 'ZapfDingbats'), plus other freely or
commonly available PostScript fonts is available along with Dvips.  To
use these fonts, you need do nothing beyond what is mentioned in the
installation procedure (see Installation).  This chapter is
therefore relevant only if you are installing new PostScript fonts not
supplied with Dvips.  (Or if you're curious.)

6.1 Font concepts
=================

The information needed to typeset using a particular font is contained
in two files: a "metric file" that contains shape-independent
information and a "glyph file" that contains the actual shapes of the
font's characters.  A "virtual font" is an optional additional file that
can specify special ways to construct the characters.  TeX itself (or
LaTeX) look only at the metric file, but DVI drivers such as Dvips look
at all three of these files.

   An "encoding file" defines the correspondence between the code
numbers of the characters in a font and their descriptive names.  Two
encoding files used together can describe a reencoding that rearranges,
i.e., renumbers, the characters of a font.

6.1.1 Metric files
------------------

A "metric file" describes properties of the font that are independent of
what the characters actually look like.  Aside from general information
about the font itself, a metric file has two kinds of information:
information about individual characters, organized by character code,
and information about sequences of characters.

   The per-character information specifies the width, height, depth, and
italic correction of each character in the font.  Any might be zero.

   In addition to information on individual characters, the metric file
specifies "kerning", i.e., adding or removing space between particular
character pairs.  It further specifies "ligature" information: when a
sequence of input characters should be typeset as a single (presumably
different) "ligature" character.  For example, it's traditional for the
input 'fi' to be typeset as 'fi', not as 'fi' (with the dot of the 'i'
colliding with 'f').  (In English, the only common ligatures are fi, fl,
ff, ffi, and ffl.)

   Different typesetting systems use different metric file formats:

   * Each Postscript font has an "Adobe font metrics" ('.afm') file.
     These files are plain text, so you can inspect them easily.  You
     can get AFM files for Adobe's fonts from
     <ftp://ftp.adobe.com/pub/adobe/Fonts/AFMs>.

   * TeX uses "TeX font metrics" ('.tfm') files.  When you say '\font =
     FONT' in your TeX document, TeX reads a file named 'FONT.tfm'.
     (Well, except for the 'texfonts.map' feature; see
     Fontmap (kpathsea)).  TeX can then calculate the space occupied by
     characters from the font when typesetting.  In addition, the DVI
     drivers you use to print or view the DVI file produced by TeX may
     need to look at the TFM file.

     TFM files are binary (and hence are typically much smaller than AFM
     files).  You can use the 'tftopl' program (see tftopl invocation (web2c))
     that comes with TeX to transform a TFM file into a
     human-readable "property list" ('.pl') file.  You can also edit a
     PL file and transform it back to a TeX-readable TFM with the
     companion program 'pltotf' (see pltotf invocation (web2c)).
     Editing metrics by hand is not something you're likely to want to
     do often, but the capability is there.

   * ATM and other typesetting systems use "printer font metric"
     ('.pfm') files.  These are binary files.  They are irrelevant in
     the TeX world, and not freely available, so we will not discuss
     them further.

   The Afm2tfm program distributed with Dvips converts an AFM file to a
TFM file and performs other useful transformations as well.  See
Invoking afm2tfm.

6.1.2 Glyph files
-----------------

Although a metric file (see the previous section) contains information
about the spatial and other properties of the character at position 75,
say, it contains nothing about what the character at position 75
actually looks like.  The glyphs--the actual shapes of the letterforms
in a font--are defined by other files, which we call glyph files.  TeX
itself only reads the TFM file for a font; it does not need to know
character shapes.

   A "glyph file" is a file that defines the shapes of the characters in
a font.  The shapes can be defined either by outlines or by bitmaps.

   PostScript fonts are defined as "outline fonts": Each character in
the font is defined by giving the mathematical curves (lines, arcs, and
splines) that define its contours.  Different sizes of a character are
generated by linearly scaling a single shape.  For example, a 10-point
'A' is simply half the size of a 20-point 'A'. Nowadays, outline fonts
usually also contain "hints"--additional information to improve the
appearance of the font at small sizes or low resolutions.

   Although various kinds of PostScript outline fonts exist, by far the
most common, and the only one we will consider, is called "Type 1".  The
glyph files for Postscript Type 1 fonts typically have names ending in
'.pfa' ("printer font ASCII") or '.pfb' ("printer font binary").

   In contrast, glyph files for Computer Modern and the other standard
TeX fonts are "bitmap fonts", generated from Metafont ('.mf')
descriptions.  The Metafont program distributed with TeX generates
bitmaps from these descriptions.

   The glyph files for TeX bitmap fonts are usually stored in "packed
font" (PK) files.  The names of these files end in '.NNNpk', where NNN
is the resolution of the font in dots per inch.  For example,
'cmr10.600pk' contains the bitmaps for the 'cmr10' font at a resolution
of 600dpi.  (On DOS filesystems, it's more likely 'dpi600\cmr10.pk'.)

   Metafont actually outputs "generic font" (GF) files, e.g.,
'cmr10.600gf', but the GF files are usually converted immediately to PK
format (using the 'gftopk' utility that comes with TeX) since PK files
are smaller and contain the same information.  (The GF format is a
historical artifact.)

6.1.3 Virtual fonts
-------------------

A "virtual font" is constructed by extracting characters from one or
more existing fonts and rearranging them, or synthesizing new characters
in various ways.  The explanation in this manual is intended to suffice
for understanding enough about virtual fonts to use them with Dvips.  It
isn't a reference manual on virtual fonts.  For more information: The
primary document on virtual fonts is Donald E. Knuth, 'TUGboat' 11(1),
Apr. 1990, pp. 13-23, "Virtual Fonts: More Fun for Grand Wizards"
('CTAN:/info/virtual-fonts.knuth'; for CTAN info, see
unixtex.ftp (kpathsea)).  (Don't be intimidated by the subtitle.)

   A virtual font ('.vf') file specifies, for each character in the
virtual font, a recipe for typesetting that character.  A VF file, like
a TFM file, is in a compressed binary format.  The 'vftovp' and 'vptovf'
programs convert a VF file to a human-readable VPL (virtual property
list) format and back again.  See vftovp invocation (web2c), and
vptovf invocation (web2c).

   In the case of a PostScript font F being used in a straightforward
way, the recipe says: character I in the VF font is character J in font
F.  The font F is called a "base font".  For example, the VF file could
remap the characters of the PostScript font to the positions where TeX
expects to find them.  See Encodings.

   Since TeX reads only TFM files, not VF's, each VF must have a
corresponding TFM for use with TeX.  This corresponding TFM is created
when you run 'vptovf'.

   You can "expand" virtual fonts into their base fonts with DVIcopy
(see dvicopy invocation (web2c)).  This is useful if you are using a
DVI translator that doesn't understand vf's itself.

6.1.4 Encodings
---------------

Every font, whatever its type, has an "encoding", that specifies the
correspondence between "logical" characters and character codes.  For
example, the ASCII encoding specifies that the character numbered 65
(decimal) is an uppercase 'A'. The encoding does not specify what the
character at that position looks like; there are lots of ways to draw an
'A', and a glyph file (see Glyph files) tells how.  Nor does it
specify how much space that character occupies; that information is in a
metric file (see Metric files).

   TeX implicitly assumes a particular encoding for the fonts you use
with it.  For example, the plain TeX macro '\'', which typesets an acute
accent over the following letter, assumes the acute accent is at
position 19 (decimal).  This happens to be true of standard TeX fonts
such as Computer Modern, as you might expect, but it is not true of
normal PostScript fonts.

   It's possible but painful to change all the macros that assume
particular character positions.  A better solution is to create a new
font with the information for the acute accent at position 19, where TeX
expects it to be.  See Making a font available.

   PostScript represents encodings as a sequence of 256 character names
called an "encoding vector".  An "encoding file" ('.enc') gives such a
vector, together with ligature and kerning information (with which we
are not concerned at the moment).  These encoding files are used by the
Afm2tfm program.  Encoding files are also downloaded to the PostScript
interpreter in your printer if you use one of them in place of the
default encoding vector for a particular PostScript font.

   Examples of encodings: the 'dvips.enc' encoding file that comes with
the Fontname distribution (<http://tug.org/fontname>) is a good (but not
perfect) approximation to the TeX encoding for TeX's Computer Modern
text fonts.  This is the encoding of the fonts that originated with
Dvips, such as 'ptmr.tfm'.  The distribution includes many other
encoding files; for example, '8r.enc', which is the base font for the
current PostScript font distribution, and three corresponding to the TeX
mathematics fonts: 'texmext.enc' for math extensions, 'texmital.enc' for
math italics, and 'texmsym.enc' for math symbols.

6.1.5 How PostScript typesets a character
-----------------------------------------

The output of Dvips is a program in the PostScript language that
instructs your (presumably PostScript-capable) printer how to typeset
your document by transforming it into toner on paper.  Your printer, in
turn, contains a PostScript interpreter that carries out the
instructions in this typesetting program.

   The program must include the definition of any PostScript fonts that
you use in your document.  Fonts built into your printer (probably the
standard 35: 'Times-Roman', 'ZapfDingbats', ...) are defined within the
interpreter itself.  Other fonts must be downloaded as pfa or pfb files
(see Glyph files) from your host (the computer on which you're
running Dvips).

   You may be wondering exactly how a PostScript interpreter figures out
what character to typeset, with this mass of metrics, glyphs, encodings,
and other information.  (If you're not wondering, skip this section ...)

   The basic PostScript operator for imaging characters is 'show'.
Suppose you've asked TeX to typeset an 'S'. This will eventually wind up
in the Dvips output as the equivalent of this PostScript operation:

     (S) show

Here is how PostScript typesets the 'S':

  1. PostScript interpreters use ASCII; therefore 'S' is represented as
     the integer 83.  (Any of the 256 possible characters representable
     in a standard 8-bit byte can be typeset.)

  2. A PostScript "dictionary" is a mapping of names to arbitrary
     values.  A font, to the interpreter, is a dictionary which contains
     entries for certain names.  (If these entries are missing, the
     interpreter refuses to do anything with that font.)

     PostScript has a notion of "the current font"--whatever font is
     currently being typeset in.

  3. One of the mandatory entries in a font dictionary is 'Encoding',
     which defines the encoding vector (see Encodings) for that
     font.  This vector of 256 names maps each possible input character
     to a name.

  4. The interpreter retrieves the entry at position 83 of the encoding
     vector.  This value is a PostScript name: '/S'.

  5. For Type 1 fonts (we're not going to discuss anything else), the
     interpreter now looks up '/S' as a key in a dictionary named
     'CharStrings', another mandatory entry in a font dictionary.

  6. The value of 'S' in 'CharStrings' is the equivalent of a series of
     standard PostScript commands like 'curveto', 'lineto', 'fill', and
     so on.  These commands are executed to draw the character.  There
     can also be "hint information" that helps adapt the character to
     low-resolution rasters.  (see Glyph files.)  The commands are
     actually represented in a more compact way than standard PostScript
     source; see the Type 1 book for details.

   This method for typesetting characters is used in both Level 1 and
Level 2 PostScript.  See the PostScript reference manuals for more
information.

6.2 Making a PostScript font available
======================================

To make a PostScript font available in a TeX document, you need to
install the font on your system and then define it within the document.
Once you have installed the font, of course, it is available for any
document thereafter and you don't need to reinstall it.  You must have
an AFM file for any font you install.  Unless the font is built into
your printer, you must also have a PFA or PFB file.

   In the following examples, we use the font 'Times-Roman' to
illustrate the process.  But you should use the prebuilt fonts for Times
and the other standard fonts, rather than rebuilding them.  The prebuilt
fonts are made using a more complicated process than that described
here, to make them work as well as possible with TeX.  So following the
steps in this manual will not generate files identical to the
distributed ones.  See PostScript font installation, for pointers to
the prebuilt fonts.

   Installation of a PostScript font proceeds in three steps.  See
Font concepts, for descriptions of the various files involved.

  1. Run 'afm2tfm' to create a TFM file for the original font, and the
     VPL form of the virtual font:
          afm2tfm Times-Roman -v ptmr rptmr

  2. Run 'vptovf' to generate a VF and TFM file for the virtual font
     from the VPL file:
          vptovf ptmr.vpl ptmr.vf ptmr.tfm

  3. Insert an entry for the font in 'psfonts.map' (see
     psfonts.map):
          rptmr      Times-Roman                 <ptmr8a.pfa

  4. Install the files in the standard locations, as in:
          cp ptmr.vf FONTDIR/vf/...
          cp *ptmr.tfm FONTDIR/tfm/...
          cp ptmr.afm FONTDIR/afm/...
          cp ptmr.pf? FONTDIR/type1/...

   The simplest invocation of Afm2tfm to make virtual fonts goes
something like this:

     afm2tfm Times-Roman -v ptmr rptmr

This reads the file 'Times-Roman.afm', and produces two files as output,
namely the virtual property list'file 'ptmr.vpl', and the "raw" font
metric file 'rptmr.tfm'.  To use the font in TeX, you first run

     vptovf ptmr.vpl ptmr.vf ptmr.tfm

You should then install the virtual font file 'ptmr.vf' where Dvips will
see it and install 'ptmr.tfm' and 'rptmr.tfm' where TeX and Dvips will
see them.

   Using these raw fonts is not recommended; there are no raw fonts in
the prebuilt PostScript fonts distributed along with Dvips.  But
nevertheless, that's how Afm2tfm presently operates, so that's what we
document here.  The 'r' prefix convention is likewise historical
accident.

   You can also make more complex virtual fonts by editing 'ptmr.vpl'
before running 'vptovf'; such editing might add the uppercase Greek
characters in the standard TeX positions, for instance.  (This has
already been done for the prebuilt fonts.)

   Once the files have been installed, you're all set.  You can now do
things like this in TeX:
     \font\myfont = ptmr at 12pt
     \myfont Hello, I am being typeset in 12-point Times-Roman.

   Thus, we have two fonts, one actual ('rptmr', which is analogous to
the font in the printer) and one virtual ('ptmr', which has been
remapped to the standard TeX encoding (almost)), and has typesetting
know-how added.  You could also say

     \font\raw = rptmr at 10pt

and typeset directly with that, but then you would have no ligatures or
kerning, and you would have to use Adobe character positions for special
letters like the ligature 'AE'. The virtual font 'ptmr' not only has
ligatures and kerning, and most of the standard accent conventions of
TeX, it also has a few additional features not present in the Computer
Modern fonts.  For example, it includes all the Adobe characters (such
as the Polish ogonek and the French guillemots).  The only things you
lose from ordinary TeX text fonts are the dotless 'j' (which can be
hacked into the VPL file with literal PostScript specials if you have
the patience) and uppercase Greek letters (which just don't exist unless
you buy them separately).  See Reencoding with Afm2tfm.

   As a final step you need to record information about both the virtual
font and the original font (if you ever might want to use it) in the
'psfonts.map' file (see psfonts.map).  For our example, you'd insert
the following into 'psfonts.map':
     rptmr      Times-Roman                 <ptmr8a.pfa

Of course, 'Times-Roman' is already built in to most every printer, so
there's no need to download any Type 1 file for it.  But if you are
actually following these instructions for new fonts, most likely they
are not built in to the printer.

   These PostScript fonts can be scaled to any size.  Go wild!  Using
PostScript fonts, however, does use up a great deal of the printer's
memory and it does take time.  You may find downloading bitmap fonts
(possibly compressed, with the 'Z' option) to be faster than using the
built-in PostScript fonts.

6.3 Invoking Afm2tfm
====================

The Afm2tfm program converts an AFM file for a PostScript font to a TFM
file and a VPL file for a corresponding virtual font (or, in its
simplest form, to a TFM file for the PostScript font itself).  The
results of the conversion are affected by the command-line options and
especially by the reencodings you can specify with those options.  You
can also obtain special effects such as an oblique font.

   Alternatives to Afm2tfm for creating virtual fonts include 'fontinst'
<http://ctan.org/pkg/fontinst>, 'lcdf-typetools', particularly
'otftotfm' (<http://ctan.org/pkg/lcdf-typetools>), and 'afm2p'
(<http://tex.aanhet.net/afm2pl/>), among others.

6.3.1 Changing font encodings
-----------------------------

Afm2tfm allows you to specify a different encoding for a PostScript font
(for a general introduction to encodings, see Encodings).  The '-t'
option changes the TeX encoding, '-p' changes the PostScript encoding,
and '-T' changes both simultaneously, as detailed in the sections below.

6.3.1.1 '-t': Changing TeX encodings
....................................

To build a virtual font with Afm2tfm, you specify the '-v' or '-V'
option.  You can then specify an encoding for that virtual font with '-t
TEX-ENC'.  ('-t' is ignored if neither '-v' nor '-V' is present.)  Any
ligature and kerning information you specify in TEX-ENC will be used in
the VPL, in addition to the ligature and kerning information from the
AFM file.

   If the AFM file has no entry for a character specified in TEX-ENC,
that character will be omitted from the output VPL.

   The '-t' option is likely to be needed when you have a PostScript
font corresponding to a TeX font other than a normal text font such as
Computer Modern.  For instance, if you have a PostScript font that
contains math symbols, you'd probably want to use the encoding in the
'texmsym.enc' file supplied with Dvips.  (For a start; to actually get
usable math fonts, you have to define much more than just an encoding.)

6.3.1.2 '-p': Changing PostScript encodings
...........................................

By default, Afm2tfm uses the encoding it finds in the AFM file.  You can
specify a different PostScript encoding with '-p PS-ENC'.  This makes
the raw TFM file (the one output by Afm2tfm) have the encoding specified
in the encoding file PS-ENC.  Any ligature or kern information specified
in PS-ENC is ignored by Afm2tfm, since ligkern info is always omitted
from the raw TFM.

   If you use this option, you must also arrange to download PS-ENC as
part of any document that uses this font.  You do this by adding a line
like the following one to 'psfonts.map' (see psfonts.map):
     zpopr Optima "MyEncoding ReEncodeFont" <myenc.enc

   Using '-p' is the only way to access characters in a PostScript font
that are neither encoded in the AFM file nor constructed from other
characters.  For instance, Adobe's 'Times-Roman' font contains the extra
characters 'trademark' and 'registered' (among others); these can only
be accessed through such a PostScript reencoding.

   The '8r' base encoding used for the current PostScript font
distribution does do this reencoding, for precisely this reason.

6.3.1.3 '-T': Changing both TeX and PostScript encodings
........................................................

The option '-T ENC-FILE' is equivalent to '-p ENC-FILE -t ENC-FILE'.  If
you make regular use of a private non-standard reencoding '-T' is
usually a better idea than the individual options, to avoid unexpected
inconsistencies in mapping otherwise.  An example of when you might use
this option is a dingbats font: when you have a TeX encoding that is
designed to be used with a particular PostScript font.

6.3.1.4 Reencoding with Afm2tfm
...............................

The Afm2tfm program creates the TFM and VF files for the virtual font
corresponding to a PostScript font by "reencoding" the PostScript font.
Afm2tfm generates these files from two encodings: one for TeX and one
for PostScript.  The TeX encoding is used to map character numbers to
character names while the PostScript encoding is used to map each
character name to a possibly different number.  In combination, you can
get access to any character of a PostScript font at any position for TeX
typesetting.

   In the default case, when you specify none of the '-t', '-p', or '-T'
options, Afm2tfm uses a default TeX encoding (which mostly corresponds
to the Computer Modern text fonts) and the PostScript encoding found in
the AFM file being read.  The reencoding is also sometimes called a
"remapping".

   For example, the default encodings reencode the acute accent in two
steps: first the default TeX encoding maps the number 19 to the
character name 'acute'; then the default PostScript encoding, as found
in the AFM file for an ordinary PostScript font, maps the character name
'acute' to the number 194.  (The PostScript encoding works in reverse,
by looking in the encoding vector for the name and then yielding the
corresponding number.)  The combined mapping of 19 to 194 shows up
explicitly in the VF file and also implicitly in the fact that the
properties of PostScript character 194 appear in position 19 of the TFM
file for the virtual font.

   The default encoding of the distributed fonts (e.g., 'ptmr.tfm')
mostly follows plain TeX conventions for accents.  The exceptions: the
Hungarian umlaut (which is at position '0x7D' in 'cmr10', but position
'0xCD' in 'ptmr'); the dot accent (at positions '0x5F' and '0xC7',
respectively); and the Scandinavian A ring '\AA', whose definition needs
different tweaking.  In order to use these accents with PostScript fonts
or in math mode when '\textfont0' is a PostScript font, you will need to
use the following definitions.  These definitions will not work with the
Computer Modern fonts for the relevant accents.  They are already part
of the distributed 'psfonts.sty' for use with LaTeX.

     \def\H#1{{\accent"CD #1}}
     \def\.#1{{\accent"C7 #1}}
     \def\dot{\mathaccent"70C7 }
     \newdimen\aadimen
     \def\AA{\leavevmode\setbox0\hbox{h}\aadimen\ht0
       \advance\aadimen-1ex\setbox0\hbox{A}\rlap{\raise.67\aadimen
       \hbox to \wd0{\hss\char'27\hss}}A}

   As a kind of summary, here are the 'CODINGSCHEME's that result from
the various possible choices for reencoding.

default encoding
          (CODINGSCHEME TeX text + AdobeStandardEncoding)

'-p dc.enc'
          (CODINGSCHEME TeX text + DCEncoding)

'-t dc.enc'
          (CODINGSCHEME DCEncoding + AdobeStandardEncoding)

'-T dc.enc'
          (CODINGSCHEME DCEncoding + DCEncoding)

The 'CODINGSCHEME' line appears in the VPL file but is ignored by Dvips.

6.3.1.5 Encoding file format
............................

Afm2tfm's encoding files have the same format as an encoding vector in a
PostScript font.  Here is a skeletal example:

     % Comments are ignored, unless the first word after the percent sign
     % is 'LIGKERN'; see below.
     /MyEncoding [ % exactly 256 entries follow, each with a leading '/'
       /Alpha /Beta /Gamma /Delta ...
       /A /B ... /Z
       ...  /.notdef /xfooaccent /yfooaccent /zfooaccent
     ] def

   These encoding files are downloaded as part of changing the encoding
at the PostScript level (see the previous section).

   Comments, which start with a percent sign and continue until the end
of the line, are ignored unless they start with 'LIGKERN' (see below).

   The first non-comment word of the file must start with a forward
slash '/' (i.e., a PostScript literal name) and defines the name of the
encoding.  The next word must be an left bracket '['.  Following that
must be precisely 256 character names; use '/.notdef' for any that you
want to leave undefined.  Then there must be a matching right bracket
']'.  A final 'def' token is optional.  All names are case-sensitive.

   Any ligature or kern information is given as a comment.  If the first
word after the '%' is 'LIGKERN', then the entire rest of the line is
parsed for ligature and kern information.  This ligature and kern
information is given in groups of words: each group is terminated by a
space and a semicolon and (unless the semicolon is at the end of a line)
another space.

   In these 'LIGKERN' statements, three types of information may be
specified.  These three types are ligature pairs, kerns to ignore, and
the character value of this font's boundary character.

   Throughout a 'LIGKERN' statement, the boundary character is specified
as '||'.  To set the font's boundary character value for TeX:

     % LIGKERN || = 39 ;

   To indicate a kern to remove, give the names of the two characters
(without the leading slash) separated by '{}', as in 'one {} one ;'.
This is intended to be reminiscent of the way you might use '{}' in a
TeX file to turn off ligatures or kerns at a particular location.
Either or both of the character names can be given as '*', which is a
wild card matching any character; thus, all kerns can be removed with '*
{} * ;'.

   To specify a ligature, specify the names of the pair of characters,
followed by the ligature operation (as in Metafont), followed by the
replacing character name.  Either (but not both) of the first two
characters can be '||' to indicate a word boundary.

   The most common operation is '=:' meaning that both characters are
removed and replaced by the third character, but by adding the '|'
character on either side of the '=:', you can retain either or both of
the two leading characters.  In addition, by suffixing the ligature
operation with one or two '>' signs, you can make the ligature scanning
operation skip that many resulting characters before proceeding.  This
works just like in Metafont.  For example, the 'fi' ligature is
specified with 'f i =: fi ;'.  A more convoluted ligature is 'one one
|=:|>> exclam ;' which separates a pair of adjacent '1''s with an
exclamation point, and then skips over two of the resulting characters
before continuing searching for ligatures and kerns.  You cannot give
more >'s than |'s in an ligature operation, so there are a total of
eight possibilities:

     =: |=: |=:> =:| =:|> |=:| |=:|> |=:|>>

   The default set of ligatures and kerns built in to Afm2tfm is:

     % LIGKERN question quoteleft =: questiondown ;
     % LIGKERN exclam quoteleft =: exclamdown ;
     % LIGKERN hyphen hyphen =: endash ; endash hyphen =: emdash ;
     % LIGKERN quoteleft quoteleft =: quotedblleft ;
     % LIGKERN quoteright quoteright =: quotedblright ;
     % LIGKERN space {} * ; * {} space ; 0 {} * ; * {} 0 ;
     % LIGKERN 1 {} * ; * {} 1 ; 2 {} * ; * {} 2 ; 3 {} * ; * {} 3 ;
     % LIGKERN 4 {} * ; * {} 4 ; 5 {} * ; * {} 5 ; 6 {} * ; * {} 6 ;
     % LIGKERN 7 {} * ; * {} 7 ; 8 {} * ; * {} 8 ; 9 {} * ; * {} 9 ;

6.3.2 Special font effects
--------------------------

Besides the reencodings described in the previous section, Afm2tfm can
do other manipulations.  (Again, it's best to use the prebuilt fonts
rather than attempting to remake them.)

   '-s SLANT' makes an obliqued variant, as in:

     afm2tfm Times-Roman -s .167 -v ptmro rptmro

This creates 'ptmro.vpl' and 'rptmro.tfm'.  To use this font, put the
line

     rptmro Times-Roman ".167 SlantFont"

into 'psfonts.map'.  Then 'rptmro' (our name for the obliqued Times)
will act as if it were a resident font, although it is actually
constructed from Times-Roman via the PostScript routine 'SlantFont'
(which will slant everything 1/6 to the right, in this case).

   Similarly, you can get an expanded font with

     afm2tfm Times-Roman -e 1.2 -v ptmrre rptmrre

and by recording the pseudo-resident font

     rptmrre Times-Roman "1.2 ExtendFont"

in 'psfonts.map'.

   You can also create a small caps font with a command such as

     afm2tfm Times-Roman -V ptmrc rptmrc

This will generate a set of pseudo-small caps mapped into the usual
lowercase positions and scaled down to 0.8 of the normal cap dimensions.
You can also specify the scaling as something other than the default
0.8:

     afm2tfm Times-Roman -c 0.7 -V ptmrc rptmrc

   It is unfortunately not possible to increase the width of the small
caps independently of the rest of the font.  If you want a really
professional looking set of small caps, you need to acquire a small caps
font.

   To change the 'PaintType' in a font from filled (0) to outlined (2),
you can add '"/PaintType 2 store"' to 'psfonts.map', as in the
following:

     rphvrl   Helvetica "/PaintType 2 store"

   Afm2tfm writes to standard output the line you need to add to
'psfonts.map' to use that font, assuming the font is resident in the
printer; if the font is not resident, you must add the '<FILENAME'
command to download the font.  Each identical line only needs to be
specified once in the 'psfonts.map' file, even though many different
fonts (small caps variants, or ones with different output encodings) may
be based on it.

6.3.3 Afm2tfm options
---------------------

Synopsis:
     afm2tfm [OPTION]... AFMFILE[.afm] [TFMFILE[.tfm]]

   Afm2tfm reads AFMFILE and writes a corresponding (but "raw", see
below) TFM file.  If TFMFILE is not supplied, the base name of the AFM
file is extended with '.tfm' to get the output filename.

   The simplest example:

     afm2tfm Times-Roman rptmr

The TFM file thus created is "raw" because it omits ligature and kern
information, and does no character remapping; it contains only the
character information in the AFM file in TFM format, which is the form
that TeX understands.  The characters have the same code in the TFM file
as in the AFM file.  For text fonts, this means printable ASCII
characters will work ok, but little else, because standard PostScript
fonts have a different encoding scheme than the one that plain TeX
expects (see Encodings).  Although the encodings agree for most
printable ASCII characters, other characters such as ligatures and
accents vary.  Thus, in practice, it's almost always desirable to create
a virtual font as well with the '-v' or '-V' option.  See Making a font available.

   The command line options to Afm2tfm:

'-a'
     By default, Afm2tfm looks for precomposed accented characters, such
     as tdieresis, and possibly adjusts the height of the basic letter
     (t) upward so that the result of using '\accent' (as in '\"t') is
     visually the same as the precomposed characters.  The '-a' option
     omits such adjustments, so that all characters' heights remain as
     they are given in the AFM file.  (Until Afm2tfm 8.4, released in
     2016, heights could also be adjusted downward, but this is no
     longer the case.)

'-c RATIO'
     See '-V'; overrides the default ratio of 0.8 for the scaling of
     small caps.

'-e RATIO'
     Stretch characters horizontally by RATIO; if less than 1.0, you get
     a condensed font.

'-O'
     Output all character codes in the 'vpl' file as octal numbers, not
     names; this is useful for symbol or other special-purpose fonts
     where character names such as 'A' have no meaning.

'-p PS-ENC'
     Use PS-ENC for the destination (PostScript) encoding of the font;
     PS-ENC must be mentioned as a header file for the font in
     'psfonts.map'.  See Changing PostScript encodings.

'-s SLANT'
     Slant characters to the right by SLANT.  If SLANT is negative, the
     letters slope to the left (or they might be upright if you start
     with an italic font).

'-t TEX-ENC'
     Use TEX-ENC for the target (TeX) encoding of the font.  Ligature
     and kern information may also be specified in FILE.  FILE is not
     mentioned in 'psfonts.map'.

'-T PS-TEX-ENC'
     Use PS-TEX-ENC for both the PostScript and target TeX encodings of
     the font.  Equivalent to '-p FILE -t FILE'.

'-u'
     Use only those characters specified in the TeX encoding, and no
     others.  By default, Afm2tfm tries to include all characters in the
     input font, even those not present in the TeX encoding (it puts
     them into otherwise-unused positions, arbitrarily).

'-v VPL-FILE'
     Output a VPL (virtual property list) file, as well as a TFM file.

'-V VPL-FILE'
     Same as '-v', but the virtual font generated is a pseudo small caps
     font obtained by scaling uppercase letters by 0.8 to typeset
     lowercase.  This font handles accented letters and retains proper
     kerning.

6.4 'psfonts.map': PostScript font catalog
==========================================

The 'psfonts.map' file associates a PostScript font with related files
and constructs.  Each line has the format:

     FILENAME POSTSCRIPT-NAME OPTIONS

   For example, the line
     rpstrn StoneInformal <StoneInformal.pfb
causes Dvips to download 'StoneInformal.pfb' (just as if it were a
header file, see Header files) if the DVI file (or a virtual font,
see Virtual fonts) references the TFM file 'rpstrn'.  The PostScript
'/FontName' of the font defined inside the 'pfb' file should be
'StoneInformal'.

   You can generate transformed fonts with a line like this:
     rpstrc StoneInformal <StoneInformal.pfb ".8 ExtendFont"

See Special font effects, for a complete list of font effects.

   You can change the encoding of the Type 1 font at the PostScript
level with a 'ReEncodeFont' instruction, plus the name of the encoding
file.  This allows you access to characters that may be present in the
Type 1 font file, but not encoded by default--most of the preaccented
characters, for example.  An example:
     pstrn8r StoneInformal "TeXBase1Encoding ReEncodeFont" <8r.enc <pstrn8a.pfb

   The '8r' encoding mentioned here has been designed to serve as a base
for all downloadable fonts; it allows access to all the characters
commonly present in a Type 1 font.  For more details, see the '8r.enc'
source file that comes with (and is installed with) Dvips.

   You may notice that the same syntax is used for downloading encoding
vectors and Type 1 font files.  To make your intentions clear, you can
also use '<[' to explicitly indicate you are downloading an encoding
vector, as in:
     pstrn8r StoneInformal "TeXBase1Encoding ReEncodeFont" <[8r.enc <pstrn8a.pfb

   If the filename of your encoding vector does not end in '.enc', and
you are using partial font downloading, you must use the '<[' syntax, or
Dvips will not download the font properly.

   Similarly, the name of the Type 1 font file itself must have
extension '.pfa' or '.pfb' for partial downloading to work properly.

   When using PFB files, Dvips is smart enough to unpack the binary PFB
format into printable ASCII so there is no need to perform this
conversion yourself.  In addition, Dvips scans the font to determine its
memory usage, just as it does for other header files (see Header files).

   If the 'j' config file or command-line option is enabled (as it is by
default), 'StoneInformal.pfb' will be "partially downloaded"--only those
characters your document actually uses will be extracted and downloaded,
and the remainder discarded.  See Option details.

   Adobe Multiple Master fonts, such as Minion, cannot be partially
downloaded.  To partially download in general, but avoid partial
downloading for individual fonts, use '<<' instead '<':
     pmnr8r Minion <<Minion.pfb

   Here is a brief summary of how 'psfonts.map' is read:

  1. If a line is empty or begins with a space, percent, asterisk,
     semicolon, or hash mark, it is ignored.

  2. Otherwise, the line is separated into words, where words are
     separated by spaces or tabs, except that if a word begins with a
     double quote, it extends until the next double quote or the end of
     the line.

  3. If a word starts with '<<', it is taken as a font file to be wholly
     downloaded.  Use this to avoid partial downloading, as described
     above.

  4. If a word starts with '<[', it is taken as an encoding file to be
     downloaded.  Use this if the name of the encoding file does end in
     '.enc', also as described above.

  5. If a word starts with a '<' character, it is treated as a header
     file that needs to be downloaded.  If the name ends in '.pfa' or
     '.pfb', it is taken as Type 1 font file that will be partially
     downloaded if the 'j' option is in effect.  There can be more than
     one such header for a given font.  If a '<' is a word by itself,
     the next word is taken as the name of the header file.

  6. If a word starts with a '"' character, it is taken as PostScript
     code used in generating that font, and is inserted into the output
     verbatim at the appropriate point.  (And the double quotes
     beginning and ending the word are removed.)

  7. Otherwise the word is a name.  The first such name is the TFM file,
     that either a DVI file or a virtual font file can refer to.  If
     there is a second name, it is used as the PostScript name and
     should match what is defined in the downloaded file; if there is
     only one name, it is used for both the TeX name and the PostScript
     name.

7 Color
*******

Dvips supports one-pass multi-color printing of TeX documents on any
color PostScript device.  Initially added by Jim Hafner, IBM Research,
<hafner@almaden.ibm.com>, the color support has gone through many
changes by Tomas Rokicki.  Besides the source code support itself, there
are additional TeX macro files: 'colordvi.tex' and 'blackdvi.tex', and
corresponding '.sty' versions for use with LaTeX.

   In this section we describe the use of color from the document
preparer's point of view and then add some instructions on installation
for the TeX administrator.

7.1 Color macro files
=====================

All the color macro commands are defined in 'colordvi.tex' (or
'colordvi.sty').  To access these macros simply add to the top of your
plain TeX file the command:
     \input colordvi
For (the obsolete) LaTeX 2.09, add the 'colordvi' style option as in:
     \documentstyle[12pt,colordvi]{article}
For LaTeX 2e, these examples are not applicable.  Instead, please see
the documentation for the graphics package, available from
'CTAN:doc/latex/graphics/'.  See also 'CTAN:doc/epslatex.ps'.

   These macros provide two basic kinds of color macros: ones for local
color changes (a few words, a single symbol) and one for global color
changes (the whole document).  All the color names use a mixed case
scheme to avoid conflicts with other macros.  There are 68 predefined
colors, with names taken primarily from the Crayola crayon box of 64
colors, and one pair of macros for the user to set his own color pattern
(see User-definable colors).  You can browse the file 'colordvi.tex'
for a list of the predefined colors.  The comments in this file also
show a rough correspondence between the crayon names and Pantones.

   A local color command has the form

     \COLORNAME{this is the color COLORNAME}

where COLORNAME is the name of a predefined color, e.g., 'Blue'.  As
shown, these macros take one argument, the text to print in the
specified color.  This can be used for nested color changes since it
restores the original color state when it completes.  For example:

     This text is normal but here we are \Red{switching to red,
     \Blue{nesting blue}, recovering the red} and back to original.

The color nesting level has no hard limit, but it is not advisable to
nest too deeply lest you and the reader lose track of the color history.

   The global color command has the form

     \textCOLORNAME

These macros take no arguments and changes the default color from that
point on to COLORNAME.  This of course can be overridden globally by
another such command or locally by local color commands.  For example,
expanding on the example above, we might have

     \textGreen
     This text is green but here we are \Red{switching to red,
     \Blue{nesting blue}, recovering the red} and back to
     original green.
     \textCyan
     The text from here on will be cyan until
     \Yellow{locally changed to yellow}. Now we are back to cyan.

   The color commands will even work in math mode and across math mode
boundaries.  This means that if you have a color before going into math
mode, the mathematics will be set in that color as well.  In alignment
environments like '\halign', 'tabular' or 'eqnarray', local color
commands cannot extend beyond the alignment characters.

   Because local color commands respect only some environment and
delimiter changes besides their own, care must be taken in setting their
scope.  It is best not to have them stretch too far.

   At the present time there are no macros for color environments in
LaTeX which might have a larger range.  This is primarily to keep the
TeX and LaTeX use compatible.

7.2 User-definable colors
=========================

There are two ways for the user to specify colors not already defined.
For local changes, there is the command '\Color' which takes two
arguments.  The first argument is four numbers between zero and one and
specifies the intensity of cyan, magenta, yellow and black (CMYK) in
that order.  The second argument is the text that should appear in the
given color.  For example, suppose you want the words "this color is
pretty" to appear in a color which is 50% cyan, 85% magenta, 40% yellow
and 20% black.  You would use the command

     \Color{.5 .85 .4 .2}{this color is pretty}

   For global color changes, there is a command '\textColor' which takes
one argument, the CMYK quadruple of relative color intensities.  For
example, if you want the default color to be as above, then the command

     \textColor{.5 .85 .4 .2}
     The text from now on will be this pretty color

will do the trick.

   Making a global color change in the midst of nested local colors is
highly discouraged.  Consequently, Dvips will give you warning message
and do its best to recover by discarding the current color history.

7.3 Color subtleties
====================

Color macros are defined via '\special' keywords.  As such, they are put
in the '.dvi' file only as explicit message strings to the driver.  The
(unpleasant) result is that certain unprotected regions of the text can
have unwanted color side effects.  For example, if a color region is
split by TeX across a page boundary, then the footers of the current
page (e.g., the page number) and the headers of the next page can
inherit that color.  To avoid this effect globally, users should make
sure that these special regions of the text are defined with their own
local color commands.  For example, to protect the header and footer in
plain TeX, use

     \headline{\Black{My Header}}
     \footline{\Black{\hss\tenrm\folio\hss}}

   This warning also applies to figures and other insertions, so be
careful!

   Of course, in LaTeX, this is much more difficult to do because of the
complexity of the macros that control these regions.  This is
unfortunate but inevitable, because TeX and LaTeX were not written with
color in mind.

   Even when writing your own macros, much care must be taken.  The
macros that 'colorize' a portion of the text work prefix the text work
by outputting one '\special' command to turn the color on before the
text, and outputting another '\special' command afterwards to restore
the original color.  It is often useful to ensure that TeX is in
horizontal mode before the first special command is issued; this can be
done by prefixing the color command with '\leavevmode'.

7.4 Printing in black/white after colorizing
============================================

If you have a TeX or LaTeX document written with color macros and you
want to print it in black and white there are two options.  On all
(good) PostScript devices, printing a color file will print in
corresponding gray levels.  This is useful to get a rough idea of the
colors without using expensive color printing devices.  The second
option is to replace the call to input 'colordvi.tex' with
'blackdvi.tex' (and similarly for the '.sty' files).  So in the above
example, replacing the word 'colordvi' with 'blackdvi' suffices.
'blackdvi.tex' defines the color macros as no-ops, and so will produce
normal black/white printing.  By this simple mechanism, the user can
switch to all black/white printing without having to ferret out the
color commands.  Also, some device drivers, particularly non-PostScript
ones like screen previewers, will simply ignore the color commands and
so print in black/white.  Hopefully, in the future screen previewers for
color displays will be compatible with some form of color support.

7.5 Color device configuration
==============================

To configure Dvips for a particular color device you need to fine tune
the color parameters to match your device's color rendition.  To do
this, you will need a Pantone chart for your device.  The header file
'color.lpro' shows a (rough) correspondence between the Crayola crayon
names and the Pantone numbers and also defines default CMYK values for
each of the colors.  Note that these colors must be defined in CMYK
terms and not RGB, as Dvips outputs PostScript color commands in CMYK.
This header file also defines (if they are not known to the interpreter)
the PostScript commands 'setcmykcolor' and 'currentcmykcolor' in terms
of a RGB equivalent so if your device only understands RGB, there should
be no problem.

   The parameters set in this file were determined by comparing the
Pantone chart of a Tektronix Phaser printer with the actual Crayola
Crayons.  Because these were defined for a particular device, the actual
color rendition on your device may be very different.  There are two
ways to adjust this.  One is to use the PAntone chart for your device to
rewrite 'color.lpro' prior to compilation and installation.  A better
alternative, which supports multiple devices, is to add a header file
option in the configuration file (see Configuration file commands)
for each device that defines, in 'userdict', the color parameters for
those colors that need redefining.

   For example, if you need to change the parameters defining
'Goldenrod' (approximately Pantone 109 on the Phaser) for your device
'mycolordev', do the following.  In the Pantone chart for your device,
find the CMYK values for Pantone 109.  Let's say they are '{\ 0 0.10
0.75 0.03 }'.  Then create a header file named 'mycolordev.pro' with the
commands

     userdict begin
     /Goldenrod { 0 0.10 0.75 0.03 setcmykcolor} bind def

Finally, in 'config.mycolordev' add the line

     h mycolordev.pro

This will then define 'Goldenrod' in your device's CMYK values in
'userdict' which is checked before defining it in 'TeXdict' by
'color.pro'.  (On MS-DOS, you will have to call this file
'mycolordev.cfg'.)

   This mechanism, together with additions to 'colordvi.tex' and
'blackdvi.tex' (and the '.sty' files), can also be used to predefine
other colors for your users.

7.6 Color support details
=========================

To support color, Dvips recognizes a certain set of specials.  These
specials start with the keyword 'color' or the keyword 'background',
followed by a color specification.

7.6.1 Color specifications
--------------------------

What is a color specification?  One of three things.  First, it might be
a PostScript procedure as defined in a PostScript header file.  The
'color.pro' file defines 64 of these, including 'Maroon'.  This
PostScript procedure must set the current color to be some value; in
this case, 'Maroon' is defined as '0 0.87 0.68 0.32 setcmykcolor'.

   The second possibility is the name of a color model (initially, one
of 'rgb', 'hsb', 'cmyk', or 'gray') followed by the appropriate number
of parameters.  When Dvips encounters such a macro, it sends out the
parameters first, followed by the string created by prefixing 'TeXcolor'
to the color model.  Thus, the color specification 'rgb 0.3 0.4 0.5'
would generate the PostScript code '0.3 0.4 0.5 TeXrgbcolor'.  Note that
the case of zero arguments is disallowed, as that is handled by the
single keyword case ('Maroon') above, where no changes to the name are
made before it is sent to the PostScript file.

   The third and final type of color specification is a double quote
followed by any sequence of PostScript.  The double quote is stripped
from the output.  For instance, the color specification '"AggiePattern
setpattern' will set the 'color' to the Aggie logo pattern (assuming
such exists.)

7.6.2 Color specials
--------------------

We will describe 'background' first, since it is the simplest.  The
'background' keyword must be followed by a color specification.  That
color specification is used as a fill color for the background.  The
last 'background' special on a page is the one that gets issued, and it
gets issued at the very beginning of the page, before any text or
specials are sent.  (This is possible because the prescan phase of Dvips
notices all of the color specials so that the appropriate information
can be written out during the second phase.)

   The 'color' special itself has three forms.  The first is just
'color' followed by a color specification.  In this case, the current
global color is set to that color; the color stack must be empty when
such a command is executed.

   The second form is 'color push' followed by a color specification.
This saves the current color on the color stack and sets the color to be
that given by the color specification.  This is the most common way to
set a color.

   The final version of the 'color' special is just 'color pop', with no
color specification; this says to pop the color last pushed on the color
stack from the color stack and set the current color to be that color.

   Dvips correctly handles these color specials across pages, even when
the pages are repeated or reversed.

   These color specials can be used for things such as patterns or
screens as well as simple colors.  However, note that in the PostScript,
only one color specification can be active at a time.  For instance, at
the beginning of a page, only the bottommost entry on the color stack is
sent; also, when a color is popped, all that is done is that the color
specification from the previous stack entry is sent.  No 'gsave' or
'grestore' is used.  This means that you cannot easily mix usage of the
'color' specials for screens and colors, just one or the other.  This
may be addressed in the future by adding support for different
categories of color-like state.