The Chemistry of Art: Scientists Explore Aged Paint in Microscopic Detail to Inform Preservation Efforts

Study involving X-ray imaging at Berkeley Lab provides clues to how artwork composed of oil paints can deteriorate over time. Watching paint dry may seem like a boring hobby, but understanding what happens after the paint dries can be key in preserving precious works of art. The formation of metal soaps in artwork composed with oil paints can cause "art acne" - including pimpling and more severe deterioration - which poses a pressing challenge for art conservation around the globe. It is affecting the works of Georgia O'Keefe, Vincent Van Gogh, Francisco de Goya, and Jackson Pollock, among many others, and researchers haven't yet found a good solution to stop its effects. To learn more about the chemical processes involved in aging oil paints in microscopic and nanoscale detail, an international team led by researchers at the National Gallery of Art and the National Institute of Standards and Technology (NIST) conducted a range of studies that included 3D X-ray imaging of a paint sample at the Advanced Light Source (ALS) , a synchrotron at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) . "An estimated 70 percent of oil paintings might already have or will have these metal-soap problems," said Xiao Ma, Charles E. Culpeper Fellow at the National Gallery of Art who was the lead author of the team's study , published in the journal Angewandte Chemie International Edition. "In our collections we see soaps in the paintings - I would say it's not uncommon," he noted.