Colour printing

In printing technology, colour printing describes a either printing process which uses multiple printing colours or individual printouts produced using a colour-printing process.

A distinction is made between:

Three colour-printing using the primary colours cyan, magenta and yellow (the CMY model)
Four colour-printing, which adds black as a printing colour (the CMYK colour model). Wet-on-wet printing applies the black colour first in order to preserve contrast levels within the image.
Multi colour-printing using a range of defined spot colours.

Primary colours, as opposed to spot colours, are also described as process colours. Colour gradation occurs during offset printing as a result of the rastering process. The colours must first be separated before this can be done.