(Cyan Magenta Yellow blacK) The color space used for commercial printing and most color computer printers. In theory, cyan, magenta and yellow (CMY) can print all colors, but inks are not pure and black comes out muddy. The black ink (K) is required for quality printing. See color space, RGB and ink coverage.
Colors Are Separated
Before printing, the image is separated into CMYK inks that blend together when printed. (Image courtesy of Intergraph Computer Systems.)
A CMYK Printer
Color laser printers use four toner cartridges. Unlike commercial printing, in which the page is printed four times, each of the four inks in a laser printer is applied to the drum, and then the page is printed.
This is a dye sublimation or thermal wax transfer ribbon where four panels of dye or wax-based ink exist for each page, and each panel is the size of the page. After printing a page, the ribbon is advanced to the next four-color set. See dye sublimation printer
and thermal wax transfer printer
CMYK and More
For greater color accuracy, inkjet printers may have one or more colors in addition to CMYK. This Canon printer has a gray cartridge. The BK cartridge is used for photos, while PGBK (page black) is used for documents.