New technique uncovers the history of a painting through the paint used
ARI SHAPIRO, HOST:
Now we turn to a detective story involving the Dutch masters and white paint. Until the 20th century, one type of white paint made from lead reigned supreme.
FRANCESCA CASADIO: There wasn't a painter for centuries that would not use lead white.
MARY LOUISE KELLY, HOST:
Francesca Casadio is a Ph.D. chemist at the Art Institute of Chicago. She says lead white, as it's called, was unparalleled.
CASADIO: It gives this dense and this rich - and it's kind of - it has a buttery consistency. So it's very opaque when you apply, and then you can do highlights. And it will, when mixed with oil, retain also the texture.
SHAPIRO: Now that paint is telling us new stories about art and the world that shaped it because lead mines in various parts of Europe extracted lead with different chemical qualities. And those different flavors of lead, or isotopes, made their way into the paint and can be differentiated in modern labs.
KELLY: Casadio likens the isotopes of lead in a paint sample to tiny, charged marbles.
CASADIO: And some are heavier, and some are lighter. And then you made them run into a track. And the lighter ones are coming in first, and the heavier ones are coming in later. And so you can count and track them.
KELLY: Scientists in Amsterdam have used that technique to analyze more than 70 Dutch paintings from 1588 to 1700, including works by Rembrandt and Rubens.
PAOLO D'IMPORZANO: Sampling many paintings made in different time give us an idea of the variation of the lead isotopes used by the artists in that time frame.
SHAPIRO: Paolo D'Imporzano of the Free University led the study in the journal Science Advances. He says changes in lead chemistry reflect changes in history, and they see that in the 1640s with the English Civil War.
D'IMPORZANO: We know that warfare was requiring a lot of lead. The civil war disrupt or change the lead supply also to produce lead white, and that's what we see in the pigments.
KELLY: Clues like that helped the team conclude that one masterpiece painted by Rembrandt's pupil Willem Drost may not have been painted during his time in Venice.
D'IMPORZANO: The isotopic signature of this painting is really similar to the one of one painting coming from a Rembrandt studio in the same period, so the painting is most likely to be from his period in Amsterdam.
KELLY: Francesca Casadio says science like this is just one clue used to solve arts mysteries.
CASADIO: It's really a sort of a detective story that needs not just one Sherlock Holmes but a team that have very different expertise - the historian, the economic historian, the art historian, the research scientist.
SHAPIRO: And as for us, the viewers, next time you visit an art museum, pay attention to the paint. It might tell a deeper story than you think.
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