To ensure that the software knows about the available media sizes and device capabilities, you must add a PostScript Printer Description (PPD) file for each device. All files that are required to support media resources are stored in the Printers folder. Information about a device's media support can be provided in any of the following files:

• PPX files: A PostScript printer extension (PPX) file can be used to expand the PPD information to allow a device to take advantage of capabilities such as custom media sizes, punch coordinates, and page positioning. If there is conflict between a PPD and PPX, the PPX is used. Not all devices need a PPX file.
• Device PPD files: When you add a media resource, a printer.ppd file stores its information inside a new folder with the same name as the nickname. If you change the configuration settings, the printer.ppd file is automatically updated. If necessary, you can edit additional settings using the PPD Browser tool that is installed with the software.
  Note: Although you can edit the supported settings, PPD files are copyrighted and should not be modified.
• Default PPD file: If the software cannot find required information in a PPD or PPX file, it uses the configuration defaults that are stored in the defaults.ppd file in the /Printers/PPD/ folder.

The software looks for information in this sequence: printer.ppd file > PPX file (if available) > device PPD file > defaults.ppd file.
Note: You can replace the pre-installed PPD files or add new PPD or PPX files. The best source for an up-to-date PPD is the device manufacturer.