Jump to content

PostScript Printer Description

From Wikipedia, the free encyclopedia
This is an old revision of this page, as edited by 89.24.197.43 (talk) at 21:09, 30 July 2011 (nowiki). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
PostScript Printer Description
Filename extension
.ppd
Internet media type
text/plain, application/vnd.cups-ppd
Magic number*PPD-Adobe
Developed byAdobe Systems

PostScript Printer Description (PPD) files are created by vendors to describe the entire set of features and capabilities available for their PostScript printers.

A PPD also contains the PostScript code (commands) used to invoke features for the print job. As such, PPDs function as drivers for all PostScript printers, by providing a unified interface for the printer's capabilities and features. For example, a generic PPD file for all models of HP Color LaserJet contains:

*% =================================
*% Basic Device Capabilities
*% =================================
*LanguageLevel: "2"
*ColorDevice: True
*DefaultColorSpace: CMYK
*TTRasterizer: Type42
*FileSystem: False
*Throughput: "10"

which specifies that the printer understands PostScript Level 2, is a color device, and so forth. The PPD can describe allowable paper sizes, memory configurations, the minimum font set for the printer, and even specify a tree-based user interface for printer-specific configuration.

CUPS

CUPS uses PPD drivers for all of its PostScript printers, and has even extended the concept to allow for PostScript printing to non-PostScript printing devices, by directing output through a CUPS filter. Such a file is no longer a standard PPD, but rather a "CUPS-PPD". CUPS clients usually read the current PPD file from the server every time a new print job is created.

Windows

Microsoft Windows also uses PPD files but converts these to a binary file format before using them. These are normally stored in C:\WINDOWS\system32\spool\drivers\w32x86\3. Updating the PPD files requires removing and then reinstalling the printer.

MIME Type

The MIME type for the CUPS variant of PPD is application/vnd.cups.ppd.[1] Apparently, this is not the case for non-CUPS PPD files, which seems to be text/plain.[2]

References