To understand how colors relate to printing, you should understand the difference between projected and reflective color.

Projected Color
Scanners and digital cameras create images using combinations of three colors: Red, Green and Blue (called “RGB”). These are the colors that computers and TVs use to display images on your screen. This is color produced by light shining out or projected color. The problem is there is no way to do “real ink on paper” printing from a file that has colors created in RGB. They must be converted to CMYK. You can convert your RGB images using an image-editing application such as Photoshop, Corel PhotoPaint or another pixel-based editing application.

Reflective Color
When an image is printed on paper a color is produced by light hitting the paper and reflecting that color (spectrum).

In the printing industry four colors are used to produce all the colors in the rainbow: Cyan (blue), Magenta (red), Yellow and Black (K) (called “CMYK”). You must start with a CMYK image or convert your RGB image to CMYK in order to produce a printed product. You can convert your RGB images to CMYK using an image-editing application such as Photoshop, Corel PhotoPaint or another pixel-based editing application.

RGB to CMYK Color Conversion
Files that have been created in RGB will need to be converted to CMYK because it is not possible to produce ink on paper printing from an RGB image. Files that were created in RGB and converted to CMYK will have a color shift. On some designs it is not very noticeable. On others the shift will stand out. During a color conversion all colors change from being built from 3 colors to being built from 4 colors. The colors are also changed from projected light to reflective light. Notice on the RGB color chart above that when all 3 colors come together the color white is produced. When all colors come together on the CMYK color chart the color black is produced.

Black Builds
Use caution when you have a solid area that is Black. Four-color process (CMYK) should be used to create a deep, dark, black, however if the total percentage of all four colors is greater than 340% your document will not print properly. Ink will saturate the stock and you will not be pleased with the final product. The only exception to this rule is text, please see the Black Text / Font information below. We have developed settings that we know work well on our presses. Please use these settings when designing your document.

The optimum settings for Black are:

• 100% Black
• 75% Cyan
• 70% Magenta
• 40% Yellow

• 100% Black
• 0% Cyan
• 0% Magenta
• 0% Yellow