More than CMYK

Many proposals have been made to extend the color gamut that can be printed with process colors cyan, magenta, yellow and the addition of black. For the most part, to illustrate the virtue of an alternate ink set, a display of the gamut is shown on the CIE chromaticity diagram indicating that a larger area is encompassed by the alternate ink set. We have chosen the Munsell color order system as a model to illustrate how certain colorants can be substituted for the conventional CMY and achieve a wider gamut in specific color areas. The substitutes are violet for yellow; orange for cyan and green for magenta. In certain areas with substitute inks, more chromatic colors can be achieved than those shown in the Munsell Book of Color which is done with pigment mixtures coated on paper.