Scientists pry a secret from the `Mona Lisa’ about how Leonardo painted the masterpiece

PARIS — The “Mona Lisa” has given up one other secret.

Using X-rays to look into the chemical construction of a tiny speck of the celebrated murals, scientists have gained new perception into the strategies that Leonardo da Vinci used to color his groundbreaking portrait of the lady with the exquisitely enigmatic smile.

The analysis, printed Wednesday within the Journal of the American Chemical Society, means that the famously curious, realized and ingenious Italian Renaissance grasp might have been in a very experimental temper when he set to work on the “Mona Lisa” early within the sixteenth century.

The oil-paint recipe that Leonardo used as his base layer to arrange the panel of poplar wooden seems to have been totally different for the “Mona Lisa,” with its personal distinctive chemical signature, the crew of scientists and artwork historians in France and Britain found.

“He was someone who loved to experiment, and each of his paintings is completely different technically,” mentioned Victor Gonzalez, the examine’s lead creator and a chemist at France’s high analysis physique, the CNRS. Gonzalez has studied the chemical compositions of dozens of works by Leonardo, Rembrandt and different artists.

“In this case, it’s interesting to see that indeed there is a specific technique for the ground layer of ‘Mona Lisa,’” he mentioned in an interview with The Associated Press.

Specifically, the researchers discovered a uncommon compound, plumbonacrite, in Leonardo’s first layer of paint. The discovery, Gonzalez mentioned, confirmed for the primary time what artwork historians had beforehand solely hypothesized: that Leonardo almost definitely used lead oxide powder to thicken and assist dry his paint as he started engaged on the portrait that now stares out from behind protecting glass within the Louvre Museum in Paris.

Carmen Bambach, a specialist in Italian artwork and curator at New York’s Metropolitan Museum of Art, who was not concerned within the examine, known as the analysis “very exciting” and mentioned any scientifically confirmed new insights into Leonardo‘s portray strategies are “extremely important news for the art world and our larger global society.”

Finding plumbonacrite within the “Mona Lisa” attests “to Leonardo‘s spirit of passionate and constant experimentation as a painter – it is what renders him timeless and modern,” Bambach mentioned by e mail.

The paint fragment from the bottom layer of the “Mona Lisa” that was analyzed was barely seen to the bare eye, no bigger than the diameter of a human hair, and got here from the highest right-hand fringe of the portray.

The scientists peered into its atomic construction utilizing X-rays in a synchrotron, a big machine that accelerates particles to virtually the pace of sunshine. That allowed them to unravel the speck’s chemical make-up. Plumbonacrite is a byproduct of lead oxide, permitting the researchers to say with extra certainty that Leonardo possible used the powder in his paint recipe.

“Plumbonacrite is really a fingerprint of his recipe,” Gonzalez mentioned. “It’s the first time we can actually chemically confirm it.”

After Leonardo, Dutch grasp Rembrandt might have used an identical recipe when he was portray within the seventeenth century; Gonzalez and different researchers have beforehand discovered plumbonacrite in his work, too.

“It tells us also that those recipes were passed on for centuries,” Gonzalez mentioned. “It was a very good recipe.”

Leonardo is believed to have dissolved lead oxide powder, which has an orange coloration, in linseed or walnut oil by heating the combination to make a thicker, faster-drying paste.

“What you will obtain is an oil that has a very nice golden color,” Gonzalez mentioned. “It flows more like honey.”

But the “Mona Lisa” — mentioned by the Louvre to be a portrait of Lisa Gherardini, the spouse of a Florentine silk service provider — and different works by Leonardo nonetheless produce other secrets and techniques to inform.

“There are plenty, plenty more things to discover, for sure. We are barely scratching the surface,” Gonzalez mentioned. “What we are saying is just a little brick more in the knowledge.”