CMYK stands for the four printing inks Cyan, Magenta, Yellow and “Key” (Black) . These four inks are the base of four-color printing. For printing colorful photos at least these four inks are required.
CMYK color spaces depend on the printer and the paper used and therefore need color profiles to describe the exact shades.
The main CMYK color spaces are:
CRPC originates from the American sector and stands for “Characterized Reference Printing Conditions”.
GRACoL and SWOP are the best known G7-based reference printing conditions. However, these two data sets do not represent the full range of inks used in the industry. The American IDEAlliance has developed a series of G7 characterization data sets that show G7 printing over a selection of common substrates. As a result of these efforts, a new standard was introduced in 2013.
CGATS 21 offers a range of G7-based reference print characterizations that represent the seven most common printing conditions:
CRPC1: gamut size and substrate of coldset news.
CRPC2: gamut size and substrate of commercial newsprint, flexo on porous substrate.
CRPC3: gamut size and substrate uncoated offset substrates with OBA.
CRPC4: gamut size of substrate SCA, offset, gravure and uncoated corrugated.
CRPC5: gamut size of and substrate of SWOP, publication gravure and wide web flexo.
CRPC6: gamut size and substrate of GRACoL, narrow web fl exo, commercial gravure, typical screen and digital.
CRPC7: gamut size of premium processes, offset, flexo, digital.