“A rare lead compound, plumbonacrite, Pb5(CO3)3O(OH)2, was detected in areas of impasto. This constitutes the fingerprint of Rembrandt’s recipe and the evidence of the use of an alkaline binding medium which sheds a new light on Rembrandt’s pictorial technique.”
To conduct the research, a team of Dutch and French scientists took small samples of paint from three Rembrandt masterpieces: Portrait of Marten Soolmans (1634), located at Amsterdam’s Rijksmuseum; Bathsheba at Her Bath (1654) from the Musée du Louvre, and Susanna (1636) housed at the Mauritshuis in The Hague. Using cutting-edge technology from the European Synchrotron lab in Grenoble, France (ESRF), they were able to pinpoint the chemicals contained within Rembrandt’s paint.
“Based on historical texts, we believe that Rembrandt added lead oxide, or litharge, to the oil in this purpose, turning the mixture into a paste-like paint,” Marine Cotte, an art conservation expert at the ESRF, told the Daily Mail.
In addition to answering a question that has plagued artists and critics for centuries, the discovery will help aid in the long-term preservation and conservation of Rembrandt's paintings going forward.