Four-color printing (CMYK)
Cyan, magenta, yellow and black (CMYK) are the inks used by a printing press. It is often called four-color printing. CMYK data files are typically used by and originate from graphic arts (printing and publishing) environments. The HP Color LaserJet 4550 series printer is optimized to print RGB colors for a good match to the screen, but will also accept CMYK colors through the PostScript printer driver.
By default, the HP Color LaserJet 4550 series printer interprets CMYK data according to the Standard Web Offset Press (SWOP) standard. This standard defines how a particular set of CMYK inks should behave. The printer performs a SWOP color map and internal half-tones to emulate a SWOP CMYK press. Emulations for Dainippon Press (DIC) and Euro-standard CMYK inks used in the Far East and Europe are also available, and can be selected from the printer driver.