Offset Printing Ink Systems-cmyk Or Spotcolor?

By Author: Dean G
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Ink Systems
CMYK Process Color: CMYK process colors use a combination of four ink colors (Cyan, Magenta, Yellow and Black) to create thousands of colors. Use process color for pieces that contain full-color photographs or when more than a few specified ink colors are used in a design.

Spot Color: Spot color inks are premixed to ensure an exact match on color. Spot colors should be used when color accuracy is critical or when only a few ink colors are needed to print a piece. Logos are commonly printed using spot color.

How Process and Spot Color Differ
The inks used for printing in CMYK process color are translucent, allowing light to pass through them, hit the paper and reflect back into the viewers eyes. Spot color inks are usually more opaque (less translucent), allowing very little light to pass through them. The light that is being reflected is done more so by the ink itself, not the paper.

Because the inks used for process color and spot color are so different they cannot be interchanged. It is a huge misconception in the industry to think that process color can be used to match a spot ...
... color. This is like trying to use watercolor paint to achieve the look and feel of an oil painting. In some cases, you are able to get a close match, but an exact match is nearly impossible due to the nature and makeup of the different types of ink.

Ink Colors and Press Plates
Each ink color used to print your piece, either CMYK process color and/or spot color will require its own plate. If you are printing in CMYK process color plus one spot color you will need five plates, one for each of the four process colors and one for the spot color. This is important to keep in mind when deciding which ink system(s) will be used to print your piece.