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A common question we get from Imation Rainbow™ Color Proofing System users is...

"Why do I need a proper viewing booth if I know that the final customers will not be using a viewing booth to look at the proofs I provide them?"

The answer...

"The only way you can be sure that the proofs you are providing are correct and consistent is if you judge them under recognized standard viewing conditions."

Reasons why standard viewing conditions must be used to ensure color correctness include the following:

• The fluorescent and reflective properties of the Rainbow™ base material can cause some perceptual color shifts in the dyes that make up the color when viewed under diverse viewing conditions. In other words, when viewed under different lighting conditions, the colors may appear to be different. This is especially true if you are trying to provide a match from Rainbow™ proofs to a different proofing product such as 3M™ Matchprint™ Color Proofing System, or to a press sheet, etc.

• Different proofing materials or different inks on printed sheets also will show perceptual color shifts under changing light conditions. And, these different products will not all provide the same amount of color shift or even shifts in the same direction.

What do we mean by "standard viewing conditions"?

For the printing industry, American National Standard (ANS) and the International Standards Organization (ISO) have specified that standard viewing conditions for color evaluations and comparisons are a 5000° Kelvin light source and a neutral gray surround. This emulates daylight and provides a balanced output of red, green and blue light.

The Rainbow™ system and ribbon dyes were designed to provide the best possible color appearance when viewed under proper 5000° Kelvin light sources.

Providing the best possible output to your customers

Even if your final customers are not viewing the proofs under correct conditions, you need to know that you have provided a properly calibrated and corrected proof and that subsequent proofing jobs will follow the same standard. If you always view the proofs under the exact same lighting conditions, you can be confident that you are providing the best possible color output to your customers.