Because of the large number of downloadable and cartridge fonts available for HP LaserJet printers, the driver can only have a few of these fonts built into it. The driver supports the installation of additional fonts by supplying a utility called the Printer Font Installer.
The Printer Font Installer adds support for soft fonts and font cartridges by installing PFM and PCM files and associated screen and soft font files. The font cartridge manufacturer can use the PFM Editor to create PFM and PCM files to accompany the font cartridge, or create these files on their own.