X-ray fluorescence spectroscopy unveils Da Vinci’s astounding sfumato technique

August 11, 2010

Mona Lisa’s mystical smile still puts viewers under a spell. Leonardo Da Vinci attained the perfection and finesse of his paintings with a technique he himself perfected. This technique is called sfumato (from the Italian for “foggy”). In this method, several layers of color are applied over each other. The colors meld together and lend the face a mysterious glow. Philippe Walter and his team at the Louvre in Paris have now examined the faces of seven paintings signed by the master with a new non-invasive X-ray fluorescence spectroscopy technique. As the scientists report in the journal Angewandte Chemie, Mona Lisa’s secret lies in many whisper-thin layers of a transparent glaze.

Da Vinci’s technique is fascinating. The gradation of color from light to dark is barely perceptible and looks natural. “Neither brushstroke nor contour is visible: lights and shades are blended in the manner of smoke,” says Walter. The details of how the sfumato technique worked have not been determined before. Walter and his colleagues have now used a non-destructive technique, X-ray , to track down the secret. The paintings were irradiated with . Every chemical element then gives off a characteristic fluorescent light, which allows the element to be quantified.

“Until now, the analysis had remained qualitative, because all the pigment layers were considered simultaneously,” reports Walter. “New technical advances and software have now allowed us to resolve cross-sections of the layers and to quantitatively analyze the composition and thickness of the individual pigment layers.” The seven paintings examined—including the Mona Lisa—span over 40 years of Da Vinci’s work.

In the Mona Lisa, the darker areas arose because a manganese-containing layer was applied more thickly than in the lighter areas. The underlying layers containing lead white are equally thick all over. In a painting dating from about ten years earlier, “Belle Ferronničre”, things are different: Here the shade effects are not the result of a glaze shining through; instead, Da Vinci seems to have used a covering layer of color—dark pigments in a classic oil technique,” says Walter. “The master continuously improved his painting technique. In his later paintings he was then able to produce translucent layers made of films of an organic medium ranging from 30 to only a few micrometers in thickness—an amazing achievement even by today's standards.” The long drying time of the individual layers, lasting weeks and months, explains why Da Vinci worked on the for over four years, leaving the painting unfinished, according to texts from the Renaissance period.

Explore further: Study: Mona Lisa neither man nor da Vinci

More information: Angewandte Chemie International Edition 2010, 49, No. 35, 6125-6128, dx.doi.org/10.1002/anie.201001116

Related Stories

Is the Mona Lisa a Self-Portrait?

January 25, 2010

(PhysOrg.com) -- Italian scientists hope to dig up the remains of Leonardo da Vinci in order to determine if his most famous painting, the Mona Lisa, is a disguised self-portrait.

Imaging method for eye disease used to eye art forgeries

February 3, 2010

Scientists in Poland are describing how a medical imaging technique has taken on a second life in revealing forgery of an artist's signature and changes in inscriptions on paintings that are hundreds of years old. A report ...

New light on Leonardo Da Vinci's faces

July 15, 2010

How did Leonardo Da Vinci manage to paint such perfect faces? For the first time a quantitative chemical analysis has been done on seven paintings from the Louvre Museum (including the Mona Lisa) without extracting any samples.

Recommended for you

Chimpanzees shed light on origins of human walking

October 6, 2015

A research team led by Stony Brook University investigating human and chimpanzee locomotion have uncovered unexpected similarities in the way the two species use their upper body during two-legged walking. The results, reported ...

The hand and foot of Homo naledi

October 6, 2015

The second set of papers related to the remarkable discovery of Homo naledi, a new species of human relative, have been published in scientific journal, Nature Communications, on Tuesday, 6 October 2015.

How much for that Nobel prize in the window?

October 3, 2015

No need to make peace in the Middle East, resolve one of science's great mysteries or pen a masterpiece: the easiest way to get yourself a Nobel prize may be to buy one.

The dark side of Nobel prizewinning research

October 4, 2015

Think of the Nobel prizes and you think of groundbreaking research bettering mankind, but the awards have also honoured some quite unhumanitarian inventions such as chemical weapons, DDT and lobotomies.

Who you gonna trust? How power affects our faith in others

October 6, 2015

One of the ongoing themes of the current presidential campaign is that Americans are becoming increasingly distrustful of those who walk the corridors of power – Exhibit A being the Republican presidential primary, in which ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.