The application of x-ray powder diffraction for the analysis of synthetic organic pigments. Part 2: artists’ paints

Abstract

Over 50 commercial paints were examined by x-ray powder diffraction in order to try and identify the synthetic organic pigments present. The binders included acrylic, oil, gum, and alkyd. Some pigments could be identified, though analysis is often complicated by the presence of large amounts of fillers and extenders in the paints relative to the small quantities of the pigment. A few of the paints did not have reflections due to fillers or extenders but the pigments could still not be identified. The best success in identifying the pigments was with acrylic binders, where the pigments could be identified in more than half of the samples examined, and with alkyds, where the pigment could frequently be identified. However, other binders, especially oil and gum, contain so many fillers that the pigment reflections are obscured. X-ray powder diffraction, therefore, is of limited utility in the identification of synthetic organic pigments in paints.