Methodological Issues and the Effect of White Pigments on Fading Introduction Lightfastness is usually reported in a single word or number—a simple answer for artists questioning a color’s permanence. Although lightfastness ratings are straightforward, lightfastness assessment is actually fairly complex, and a variety of factors can influence both laboratory and real-world lightfastness outcomes. To tackle … Continue reading ASTM Lightfastness Testing for Oil Paints