One of the most famous paintings from the Dutch Golden Age is Rembrandt van Rijn’s 1642 masterpiece The night watch. An interdisciplinary team of researchers conducted an extensive new analysis and found rare traces of a compound called lead formate in the paint, according to a recent paper published in the journal Angewandte Chemie. The work was part of the Rijksmuseum’s Operation Night Watch, the largest multidisciplinary research and conservation project ever undertaken for Rembrandt’s famous painting, dedicated to its long-term preservation.
“In Operation Night Watch, we focus on Rembrandt’s painting technique, the state of the painting and how best to preserve it for future generations,” said Katrien Keune, science manager at the Rijksmuseum and professor at the University of Amsterdam (Netherlands). “Lead formate gives us valuable new clues about Rembrandt’s possible use of lead-based oil paint and the potential impact of oil-based varnishes from past conservation treatments, and the chemistry complex of historic oil paintings.”
Science has become an invaluable tool for art curators, especially various X-ray imaging methods. For example, in 2019 we reported how many oil paintings from the Georgia O’Keeffe Museum in Santa Fe , in New Mexico, had been developing tiny pin-sized blisters, almost like acne, for decades. Conservationists and academics first assumed that the imperfections were grains of sand trapped in the paint. The chemists concluded that the blisters are actually metal carboxylate soaps, the result of a chemical reaction between metal ions from lead and zinc pigments and fatty acids from the binder used in the paint. The soaps begin to clump together to form blisters and migrate through the paint film.
Restorers have seen similar deterioration in oil-based masterpieces from all eras, including works by Rembrandt. For example, the Metropolitan Museum of Art in New York has an ongoing project to determine the causes and mechanisms of metallic soap formations on traditional oil paintings; he collaborates with scientists at Brookhaven National Laboratory to analyze samples using nuclear magnetic resonance spectroscopy and synchrotron-based X-ray methods.
In 2020, scientists analyzed the work of Edvard Munch The Scream (which showed alarming signs of degradation) and concluded that the damage was not the result of exposure to light, but to humidity, particularly from the respiration of museum visitors, possibly as they bent down to take a closer look at the master’s brushstrokes. In March 2022, scientists studied the deterioration of Jean-Baptiste-Camille Corot’s disease Mandolin Gypsy (circa 1870). They used three complementary techniques to analyze paint samples under infrared light to determine the composition of harmful metal carboxylate soaps that had formed on the top layer of paint.
. scientists identify of compounds lead rare in Night Watch Rembrandt