This is a common color-matching problem and it is caused by Metamerism. Because colors can be created by using different mixtures of pigments and dyes, the combination of dyes or pigments used will determine how well colors match under different light sources. The greatest effect of metamerism can be seen when viewing a sample under a predominantly Blue source (e.g., D65) and a predominantly Red/Yellow source (e.g., Illuminant A). If the same dyes are used, no metamerism should be seen. If different dyes are used to create the same color, metamerism is possible. When comparing different samples, one colored using dyes and one colored using pigments (evaluating a textile sample next to a paint sample for instance), metamerism is not uncommon. Finding the right “mix” of dyes and pigments is part of the color technologists job. Sometimes, metamerism cannot be eliminated completely, only reduced.

Yes. Although color-matching booths from GTI Graphic Technology, Inc. come standard with the Munsell N7 surround, both white and black insert panels are available at reasonable costs. These fit into the booth quickly and easily and are easily removable.

Industry standards specify the surround for critical color applications should be Munsell N7 gray. A chromatic color (e.g., Red, Green, Blue) will influence and bias the color perception of the viewer. For this reason, an achromatic color (black, white or gray) surround is needed. Munsell N7 is a medium gray tone, about halfway between black and white. Therefore, it works well for almost all color matching applications. When extremely light colors need to be matched (light pastel colors for instance) a white surround should be used. For very dark samples or for samples with high gloss, a black surround should be used. Color matching booths from GTI Graphic Technology, Inc. have a Munsell N7 surround. When other booth surrounds are needed, GTI offers white and black panel inserts to quickly convert the booth from the Munsell N7 to the appropriate surround.

No, they can be plugged in to any normal outlet with a rating of at least 10 Amps. However, due to the use of electronic ballasts for the fluorescent lamps, they should never be plugged into a battery back-up system (Uninterrupted Power Supply).

Yes, especially if optical whitening or brightening agents are present, or might be present, in the articles to color match.