What is “Encapsulated PostScript” (“EPS”)?
PostScript has been for many years a lingua franca of powerful
printers (though modern high-quality printers now tend to require some
constrained form of Adobe Acrobat, instead); since PostScript is also a
powerful graphical programming language, it is commonly used as an
output medium for drawing (and other) packages.
However, since PostScript is such a powerful language, some
rules need to be imposed, so that the output drawing may be included
in a document as a figure without “leaking” (and thereby destroying
the surrounding document, or failing to draw at all).
Appendix H of the PostScript Language Reference Manual (second
and subsequent editions), specifies a set of rules for PostScript to
be used as figures in this way. The important features are:
A PostScript figure that conforms to these rules is said to be in
“Encapsulated PostScript” (EPS) format. Most (La)TeX packages for
including PostScript are structured to use Encapsulated PostScript;
which of course leads to much hilarity as exasperated (La)TeX users
struggle to cope with the output of drawing software whose authors
don’t know the rules.
- certain “structured comments” are required; important ones are
the identification of the file type, and information about the
“bounding box” of the figure (i.e., the minimum rectangle
- some commands are forbidden — for example, a
command will cause the image to disappear, in most TeX-output
- “preview information” is permitted, for the benefit of things
such as word processors that don’t have the ability to draw
PostScript in their own right — this preview information may be in
any one of a number of system-specific formats, and any viewing
program may choose to ignore it.
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=eps