Ink Tips Color differences will occur when the same PMS color is applied to a coated and uncoated sheet of paper. Color differences will occur if you apply the same PMS color on a gloss, silk/dull or matte finish coated sheet. Process colors are created by using different percentages of the four process ink colors (Cyan, Magenta, Yellow and Black). Spot Colors are a blend of as many as 15 different base ink colors. Ink when used as a solid is slightly translucent. Coated paper has a coating on its surface. Uncoated does not have a coating. Coated paper is identified as gloss, silk/dull or matte. Pantone colors are identified by a number (032), which represents the color and a letter (c or u) which stands for coated or uncoated. Occasionally you will see m which stands for matte. Coating makes coated paper less absorbent. Because of this ink will appear richer and more vibrant in color. Uncoated paper absorbs ink causing the ink not to appear as rich and vibrant. Pantone 021C and 021U have the same formulation they just appear differently on coated and uncoated sheets of paper. Remember, make sure you know the ink color differential that will occur if you change paper. Especially if you are going from a coated to an uncoated paper stock.