Full Color Preseparated Art: Process Colors


Additive primary colors

The process of overprinting greatly reduces the number of plates that are required to print full color artwork. In fact, nearly all colors can be created by overprinting just three colors of ink in varying tones.

The visible spectrum can be broken down into three main color components: red, green, and blue. Combining these colors of light will create a new color: orange is a combination of red and some green, violet a combination of blue and some red, and so on. Combine all three and you have white. As a result, red, green, and blue are called additive primary colors.


Subtractive primary colors

Although the additive primary colors can be used to create different colors of light, they do not function the same way as ink. Combining red and green light creates yellow, but combining red and green ink creates a dark, muddy brown. As a result, a different set of primary colors are used in printing. These are known as subtractive primary colors because they are the colors that result from removing a single additive primary from white light; they are created by the combination of the remaining two colors and are cyan (green and blue), magenta (red and blue), and yellow (red and green).


Pages from a chart showing the colors that result from overprinting cyan, magenta, and yellow inks at different percentages.

Subtractive primary color inks can be combined to print nearly any color. Black ink is usually added to strengthen these colors and print any accompanying text.1 Collectively these four inks are known as process colors (cyan and magenta were often referred to incorrectly as blue and red). This technique of printing is known as four color process printing, sometimes referred to as CMYK for cyan, magenta, yellow, and k for black.

Most printers can provide color charts showing the colors that result from overprinting process color inks in various percentages. The artist could select a desired color from the chart and break it down into the percentages of each color of ink required to print it. Color separations could then be made by carefully indicating percentages of ink on overlays.2


Ink illustration

Jose Aruego and Ariane Dewey's illustrations from The Chick and the Duckling at the beginning of this exhibit are an example of preseparated art for four color process printing, as is this example of the same artists' work from Mitchell Sharmat's book Gregory, the Terrible Eater.

In both cases, Mr. Aruego created the black line drawing used on the key plate. Ms. Dewey then created the intricate overlays that give the books their color, one each for cyan, magenta, yellow, and black. These overlays were created using special grey paints that represent different percentages of ink. This was a laborious process; it took Ms. Dewey about two months to produce the artwork for this book.3

Ariane Dewey discusses how she made Gregory, the Terrible Eater with Ava Weiss and Paul Zelinsky

Ms. Dewey used a color chart to select the colors she wanted in the printed book and relied on detailed notes for the more complicated areas of the illustration.

The creation of preseparated art allowed the camera person to photograph each overlay and print with a full range of strengths for each color. When the various tints are combined by overprinting the result is a printed page that looks like a reproduction of full color art.

1. Craig, James. Production for the Graphic Designer. New York: Watson-Guptill Publications, 1974. Print. 108-109 

2. Shulevitz, Uri. Writing with Pictures: How to Write and Illustrate Children's Books. New York: Watson-Guptill Publications, 1985. Print. 215-217 

3. Dewey, Ariane. "Re: Wow! Thank You!" Message to Lisa Von Drasek. 3 Decemebr 2015. Email. 

Full Color Preseparated Art: Process Colors