The format of this preview representation varies from system to system. It
is typically a Macintosh PICT resource, a TIFF file, or a device-independent
hex bitmap. If the EPS file does not provide a preview image, the application
that includes the EPS file must provide a representation of the preview, such
as a gray box that represents the extent of the EPS file. The end user can use
the screen preview to position and size the EPS file in the document.
To support encapsulated PostScript files effectively, some cooperation is
required among the applications that
produce
EPS files and those that
use
EPS files. Typically, EPS files are used by importing (or including) them in
other documents.
All DSC comments in an EPS file communicate information. How an appli-
cation uses this information is up to the programmer of the including applica-
tion. When importing an EPS file, do not reduce the amount of information in
the EPS file by improperly removing or altering DSC comments. In general,
the comments indicate what resources and language extensions are used,
and where they are used in the EPS file. Encapsulated PostScript files are
final-form print files that do not know anything about the printer on which
they will be imaged. If they have specific resource needs, such as fonts,
these needs must be carefully preserved and addressed.
Any application that generates PostScript language programs is potentially
both a
consumer
and a
producer
of encapsulated PostScript files. It is proba-
bly best not to think that an application is at either end of the chain. If an
application imports an EPS file, it is responsible for reading and understand-
ing any of the resource needs of the imported EPS file. These needs must be
reflected in the resource usage comments of the composite document the
including application creates. For example, if an imported EPS file uses
Lithos™, but the rest of the document is set in Times-Roman, then by import-
ing the EPS file, the document now also uses the Lithos font. This fact must
be reflected in the composite document’s outermost
%%DocumentNeeded-
Fonts:
comment. This concept holds true for the
%%DocumentNeede-
dResources:
,
%%LanguageLevel:
and
%%Extensions:
comments as well.
2
Guidelines for Creating EPS Files
To be considered a conforming EPSF version 3.0 file, a file must follow the
rules set forth in this appendix, be a
single
page document that fully conforms
to the DSC version 3.0 or later (described in the
PostScript Document
Structuring Conventions Specifications
available from the Adobe Systems
Developers’ Association), and include two required DSC header comments.
2.1
Required DSC Header Comments
The two required DSC Header comments are
2 Guidelines for Creating EPS Files
7