Choosing the most pleasing or effective color combinations is only part of the equation in working with color. You must also be able to specify the colors you want. For printing there are a number of ways to specify color and it can vary depending on the number of colors used and how you use them. We'll just go through a few of the possibilities.
- Tints of a Single Color You can achieve a large variety of effects using a single spot color (1/C) by specifying that the color be screened (tints). These tints are percentages of the solid color (100%).
- Two or More Colors Combine solids and screened tints of two or more colors (2/C, 3/C, 4/C etc.). In the example,above, the colors are all combinations of a single color plus black (K) (top three are cyan, bottom three are magenta). (for printing purposes black is a color) They are also percentages.
- PMS Colors To match a color exactly (or as near as printing can get) you can use a system such as the Pantone Matching System. There are others as well. Color mixes are numbered for easy reference. Your graphics program may have color palettes named for some of the more popular color-matching systems. These allow you to choose colors for your design that correspond to the color-matching system your printer uses. See PANTONE Spot Color Name Suffixes for more on PMS colors. (Note that the color names/numbers in the image may not reflect the most current designations from Pantone.)
- CMYK In four-color process printing, to reproduce full-color continuous-tone color, we use four specific colors. These process colors are cyan (C), yellow (Y), magenta (M) (the SUBTRACTIVE colors from our color wheel), and black (K). The perception of millions of colors is achieved not by mixing these colors of ink but by printing thousands of tiny dots of each color in different sizes and patterns. The eye merges those dots and sees more than the four colors of CMYK (or sometimes written as, CYMK).
- Color Separations In four-color process printing, rather than specifying specific colors, you create a different copy of your artwork for each of the four colors (CMYK). Each copy is printed one on top of the other to create the optical effect of full-color. Separations are also created when using more than two spot colors with each separation containing only the parts of the page for that specific color. In the illustration, the 4 grayscale images represent the printing plate for each of the 4 process colors. Notice how the Magenta plate is much darker on the body of the tractor? It takes a lot more of this reddish color ink to produce the bright red tractor. Learn more about separations.
Obviously this is only a quick overview. Hundreds of books and articles have been written about the process of specifying and printing in color. See the links at the end of this article for more in-depth coverage.
Color Basics Index: