An easy-to-use method for preparing paint cross sections

Abstract

ABSTRACTThe optimized method for preparing paint cross sections described here advances our understanding of the structure of multilayered modern and contemporary paintings. Conducted in micrometer scale with nondestructive characterization, this method of sample preparation preserves the morphological integrity of the paint layers, while achieving a high-quality surface suitable for imaging and inorganic mapping studies. The preparation begins by positioning the paint cross section face down on a restickable, double-sided acrylic adhesive dot affixed to a glass slide. A molded nylon ring is then placed around the sample and filled with Bio-Plastic resin. After curing, the sample is released from the ring. The paint layers are fully exposed because the dot does not bond with the cured resin. The sample requires minimal dry polishing for a high-quality surface because the cross section is not fully embedded in the resin; instead, the face of the cross section sits at the resin’s surface. These samples can be prepared in one day. In this study, we obtained data from a single paint sample from the twentieth century painting The Big Egg (1968) by Ed Clark, from the Smithsonian’s National Museum of African American History and Culture (NMAAHC). At least 15 layers were identified from one paint sample and were characterized using digital microscopy and SEM–EDS.