
The Role of Printer Drivers
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ese are all good reasons why embedding entire CJKV fonts has been dicult to imple-
ment and is simply not practical. Some printer driver are responsible for performing font
subsetting, which consists of three basic steps:
Determine what glyphs in a given font are used in the requested document.•
Create a new version of the font that contains only the glyphs for the characters ref-•
erenced in the document.
Embed the newly built subsetted font into the PostScript le.•
Adobe Acrobat, as a medium for creating, displaying, and printing PDF les, also sup-
ports font subsetting. When a PDF le is created, only the glyphs that are referenced in
the document are embedded.
Microsoft Windows Printer Drivers
In the past, the availability of appropriate printer drivers on Windows was critical in get-
ting your documents to print correctly. Windows had traditionally been a platform that
did not allow the printer driver to query the printer. is is why the infamous PostScript
Printer Description (PPD) les were absolutely necessary.
PPDs contain the printer’s conguration information in a convenient (and local) form
that can be easily understood (that is, parsed) by printer drivers. PPDs are, in general,
read-only documents, but some applications retain their own set of writable PPDs in or-
der to manage fonts that have been subsequently added (that is, aermarket ...