Four-color process is ideal when an imprint calls for full-color artwork or includes photographs, due to its ability to print a wide range of colors. In preparing art for production, the image is rendered in overlapping combinations of inks using the CMYK color model. CMYK stands for cyan, magenta, yellow, and key black. Every color in the original art can be reproduced with the proper proportional mixture of these four ink colors in variable levels of intensity on the pixel level, with subtle shading accomplished through halftoning.
While the four-color process is excellent for reproducing images faithfully, the colors produced by the CMYK procedure will not yield the exact shades that PMS color matching does, therefore we cannot guarantee PMS matching when using this process.