A Zeiss Universal polarizing microscope is used in the study of pigments, paper, textile and wood fibers to answer questions arising during the treatment of paintings or other works of art. Sectional fragments and scrapings from paintings are mounted in Aroclor 1260 and 5442. Pigments are identified by their crystallographic properties. Mentions terre verte (glauconite), lead white, calcium carbonate, anhydrite, Naples yellow, leadtin yellow, iron oxide yellow earth, verdigris, vermilion, azurite, bone black, flax (5th century Coptic), Tilia vulgaris (European limewood). Samples from paintings by David, Hals and Holbein. (See also <i>AATA 9-1 and 10-526). -- AATA