Running Linux, 5th Edition - Matthias Kalle Dalheimer [274]
Unfortunately, most printers, and particularly the inexpensive consumer and small business printers that are often paired with Linux, don't understand PostScript. The answer is to pipe output through Ghostscript (http://www.cs.wisc.edu/~ghost/), which is a PostScript interpreter that can reside on the computer rather than in the printer. Ghostscript converts PostScript into formats that most printers can understand. In effect, the combination of PostScript and Ghostscript becomes the Linux equivalent of the Windows printer driver system.
Although CUPS changes many things about the Linux printing system, it still relies on Ghostscript to convert PostScript into printers' native languages. Thus, you must have Ghostscript installed on your system if you expect to print to a non-PostScript printer. Fortunately, all major Linux distributions ship with Ghostscript. You may want to check to be sure it's installed, though; look for a package called ghostscript.
Ghostscript is actually available in two versions. The most recent version of Ghostscript is AFPL Ghostscript, which is available under a license that permits free use for many purposes, but not free redistribution. After a few months, AFPL Ghostscript is released under the GPL as GNU Ghostscript, and it's this version that comes with most Linux distributions. In most cases, being a few months behind the leading edge of Ghostscript development is unimportant. If you absolutely must have the latest version, though, check the Ghostscript home page.
Ghostscript comes with drivers for many common printers , and it can also output many common graphics file formats. You can even generate Adobe Portable Document Format (PDF) files with Ghostscript. (The ps2pdf shell script helps automate this process.) For more flexibility, you can add Ghostscript drivers for assorted printers.
As a point of interest, you should know that Ghostscript treats all printers as graphics devices. That is, if you print a purely textual document, Ghostscript converts that text into a graphics bitmap and sends the bitmap to the printer. This means that Ghostscript cannot take advantage of fonts that are built into the printer. It also means that Ghostscript sometimes prints more slowly than other software, such as Windows drivers, can print to the same printer. (This effect is usually negligible, but it's sometimes dramatic.) On some very old laser printers, another consequence is that Ghostscript (and hence Linux) requires a printer memory upgrade for the printer to print at full resolution. In practice, though, even Windows treats many printers as graphics-only devices, so Ghostscript's doing so may not make any difference.
Printer definitions
A standard CUPS installation supports a fairly narrow range of printers, typically PostScript models and some Hewlett-Packard and Epson printers. To support more printers, you must install a printer driver package. (In truth, many of these "drivers" are really just printer descriptions coupled to standard Ghostscript drivers, but in practice they're necessary either way.) Several such driver packages exist:
Foomatic
These drivers, headquartered at http://www.linuxprinting.org/foomatic.html, handle many popular printers. They're a good place to start for many printers.
GIMP Print
The GNU Image Manipulation Program (GIMP) is a popular graphics package that's developed its own set of printer drivers. These have been spun off into a separate printer driver package that can be used with CUPS (or with BSD printing systems). The GIMP Print drivers are often particularly good choices if you want to print graphics. Check http://gimp-print.sourceforge.net for more information.
ESP Print Pro
The original CUPS developers have made a set of printer definitions available on a commercial