A review on the color measurement and interpretation of special effect coatings

Special effect coatings exhibit differences in their perceived color with changes in the illumination or viewing angle, giving them a very appealing appearance. These coatings consist of a transparent substrate having embedded absorption pigments, which absorb part of the light, and pearlescent pigments, which have a selective reflection due to their flake-shaped structure. So, a set of measurement geometries are required to completely characterize these coatings. The combination of one illumination angle and three viewing angles are sufficient for the colorimetric characterization of metallic coatings but are not sufficient for the characterization of special effect coatings. The review paper describes new concepts for the characterization of special effect coatings.