The white paint are the most desirable coating in the paint industry. The more it is plain to the wall, more it can generate issue of metamerism. Comparative to white color, other colors which also inhibit the issue of metamerism have a limit up to which they can change their appearance as per the lighting conditions. But in case of White paint, the changes has no limit. And also it is near to impossible to fix the color to appear white in every lighting condition. But what manufacturers can at least do is that limit the changes.
It is not at all possible for them to control up to an extent where the white paint will appear white under natural daylight and under red light. But what can be done is that it must appear its natural look under daylight and under fluorescent tube light. To control the consistency of white paint, Color matching box is utilized. The test equipment is a cabinet constructed using high grade steel material plated with corrosion resistant coating for life long expectancy of the machine.
It is equipped with five different source of lights for studying the issue of metamerism. These lights are selected as per the test requirement of Asian lighting conditions. It includes D65 artificial daylight which can be considered for testing the specimen under natural daylight conditions. Then there is UV black light, to understand how the coating behaves when exposed to UV light. Other than these, there is tungsten filament light which delivers a yellowish appearance. Usually this type of light is seen coming from the bulb.
Also, it has a cool white fluorescent light which is commonly exerted from tube lights. And last is the Triphosphor Fluorescent Light or TL 84 light. Under these lighting condition the specimen is placed and seen that how the appearance changes under the lighting conditions. Also the cabinet allows a specific angle of placement for the specimen. The specimen platform is kept at a specified angle of 45 degree for a clear and accurate inspection. The angular inspection platform holds lots of importance and ensure zero errors in testing.