Methods of pigment evaluation are described that should be useful for those formulating paint with organic pigment colors.
This report on the evaluation of 17 commonly used organic color pigments is of interest in several respects. First, it provides relevant test methods and procedures particularly suited to paint laboratories. Second, it reports the effects of more than two years weathering when all of these pigments were exposed side by side in an alkyd enamel formulation at two levels of color pigment loading. Third, by employing uniform pigment loadings throughout, comparisons of both durability and optical properties are facilitated. And fourth, the formula design keeps pigment loading equal between each tint formula and each deeper color formula for the same pigment; this permits the evaluation of the effects of pigment loading on gloss, viscosity and other properties.