July 19, 2019
Various Light Sources and Their Use in Color Matching
Proper lighting is essential for effective color matching because the appearance of an object is significantly influenced by the light source and the environment in which it is viewed. Daylight, store light, and home light are a few examples of common light sources that are being used in color matching applications. Regardless of what type of lighting is used, all stakeholders in a supply chain need to evaluate a color under a consistent light source in order to communicate with each other. To help achieve this goal industries have developed international standards for the viewing of color.
When Color Matching Matters Most
The two primary standards are ISO 3664:2009 and ASTM D1729. ISO 3664:2009, which specifies a D50 daylight viewing condition, is used by the graphic arts and photographic industries. ASTM D1729, which specifies D65 as the primary daylight viewing condition and others as secondary sources to check for metamerism, has been adopted by many industrial color applications including plastics, paints, coatings, and textiles. Other standards such as SAE J361 and BS-950 Part 2 are used in select applications.
Metamerism occurs when two colors match under one lighting condition but not under another. This can be a problem for manufacturers and shows the importance of evaluating colors and color matches under spectrally dissimilar light sources in addition to the daylight source specified by your industry’s specification.
Conditions that Affect Color Appearance
Industry standards require that viewing conditions meet strict specifications with regard to color quality, light intensity, evenness of illumination, viewing/illumination geometry, and surrounding conditions. Differences in any of these conditions can affect color appearance. The best way to ensure that you meet these requirements is to use a color viewing booth that meets industry specifications. GTI’s industry compliant product portfolio includes desktop viewers, floor stand models, and color harmony rooms. A wide range of products are available for both the industrial color and graphic arts markets.
Lamps are the key element of any viewing environment. GTI’s Graphiclite 100 5000K viewing lamps and ColorMatcher 6500K Color Matching Lamps are designed for use in color viewing stations and color matching booths and deliver the tightest match to the industry standard curves. The lamps are manufactured with a unique blend of fluorescent phosphors and produce a true full spectrum white light which renders colors with the highest degree of accuracy and efficiency. These lamps provide greater color fidelity and tighter compliance to the viewing standard than competitive lamps. All products with GTI lamps comply with industry standards and are shipped with a certificate of product conformance (NIST traceable).