The Da Vinci Question

Close-up of La Bella Principessa

A closeup of the eye from the portrait. Image courtesy Science Television Workshop.

Cotte, no stranger to da Vinci’s work, is responsible for the 2004 “virtual unvarnishing” of the Louvre’s Mona Lisa. He also scanned Lady with an Ermine, which now hangs in the Czartoryski Museum in Kraków, Poland. When we arrived, he showed us Lumiére’s work on these two famous paintings. In the Mona Lisa we saw how da Vinci changed the hands and the delicacy of the veil over her hair for the final version. Women of that time wore such a veil when pregnant, so perhaps the woman with the famously enigmatic smile was with child. On the scans of Lady with an Ermine we saw a fingerprint. Kemp commented that Leonardo worked with his hands all the time, as many artists do, their fingers not only touching and holding the canvas but also coaxing paint and other materials across it.

Finally Cotte revealed the digital image we had traveled all this way to see: the portrait of the young woman, which had been scanned at about 4,000 pixels per square millimeter. That resolution meant the scans could be examined in great detail. At that time she was named Profile of a Young Fiancée, as she was thought to be a sort of profile of the Renaissance—a portrait made to show an interested fiancé the attractiveness of his potential bride. Providing such portraits before marriage was a common practice during the Renaissance. But as we looked more closely, we began to hold our breath.

On the left side of the portrait was an uneven edge cut not by scissors but by a knife. We could even see where the knife had slipped. We also noticed three small holes with tattered edges on the left side of the sheepskin, suggesting that this portrait might have been the cover of a handmade bound booklet.

“That’s incredibly interesting,” Kemp said. “This could have been the frontispiece for a manuscript of Petrachian-type poems written in honor of this young woman. That would explain the sheepskin.”

We examined the portrait in greater detail, starting with the woman. Creating skin tones on a yellowish sheepskin, or vellum, had to be different than painting on a white canvas, Leonardo’s usual style. Cotte told us that scans of the skin-tone areas revealed white lead, red, and green pigments, but no yellow; instead the artist used the vellum itself as the source for the yellow of the skin tones, a technique Kemp suggested might have been learned from Jean de Perréal, a manuscript artist from Paris. A note in Leonardo’s Codex Atlantius contains the intriguing hint that he wrote to de Perréal requesting information on how to create realistic skin tones on vellum.

Her eye—in a shade of amber provided solely by the color of the sheepskin—was framed by tiny wisps of eyelashes drawn in precise, delicate lines with sharply pointed, hard, black chalk. The design on the dress and the hairs on the woman’s head were also drawn with chalk. The coloring of the skin, hair, and dress, however, was done with organic dyes.

As we explored more of the portrait’s handiwork we found left-handed “hatching”—tiny parallel lines used for shading, which are uniquely Leonardo’s. Although some of Leonardo’s Milanese and Florentine followers tried to emulate his hatching style, none came close to his precision. Cristina Geddo, an Italian expert on the works of Leonardo’s followers, confirmed that there were no left-handers in that group and, after studying scans of the portrait online, told Kemp that none of the followers ever reproduced the same sublime results as Leonardo.

Further evidence for consideration was the young woman’s dress, revealing her to be an upper-class Milanese lady of the late 15th century. The greens, reds, and whites of the dress represent the colors of the ruling Sforza family, while the elaborate knot-design detail on the dress is typical of design details favored by Leonardo. Her hair was arranged in a style created by Beatrice, the young wife of Ludovico Sforza, the duke of Milan and Leonardo’s patron, and was called a coazzone, or plait.