Colorimetric characterization of pearlescent coatings

Abstract

This paper describes recent developments at the National Institution of Standards and Technology in the colorimetric characterization of pearlescent coatings. The goal of this research is to develop a measurement protocol for the accurate color characterization of these coatings using an understanding of their scattering mechanism as a guide. The bi-directional reflectance of a series of samples has been measured for the visible region at incident angle of 15°, 25°, 45°, 65°, and 75° and viewing angles of +/- 80° at 5° steps. This large ensemble of measurements show general trends in the color variations with incident and viewing angles that are being used to define a preliminary subset of measuring geometries that will provide sufficient information to characterize the angle dependent color travel in pearlescent coatings.