Wednesday, June 17, 2009

Four Color Process

Did you know that most of the images you see on our trading cards are reproduced using only four inks? During the printing process, four inks are used in combination to reproduce the images you see on the card: cyan, magenta, yellow, and black. If you take a magnifying lens and look closely, you will see many series of “dots” that actually make up the image. The dots are typically small enough that our eyes don’t see them but instead they see the overall picture. Through the use of computer programs, a continuous tone photograph is separated into the four colors listed above. When the colors are printed using dot patterns and overlaid together, the image is recreated and our eyes see what appears to be an image with thousands or millions of different colors. Check out the below two images. The first slice is cyan only, followed by cyan + magneta, cyan + magenta + yellow, then all four colors. In the second image, the dots have been magnified.

Even with these four colors though, there are still certain hues that cannot be reproduced. Deep oranges and greens are typically outside the range of four color printing. Another process called hexachrome utilizes the four colors of ink plus two additional colors to extend the gamut. Usually orange and green are added. While useful for specialized images or high end looks, hexachrome is not as cost effective and therefore used only occasionally.

Other spot colors are used on a regular basis. For example, we use white inks when printing on foil or plastic substrates. Sometimes certain spot colors called metallic inks are used which actually contain tiny bits of metal flake. These give a specialty look without the expense of foil stamping or foil board.

So the next time you see someone looking at a card with their magnifying glass, they might just be checking out the dots!

No comments: