Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mona Lisa’s Secret

11.08.2010
X-ray fluorescence spectroscopy unveils Da Vinci’s astounding sfumato technique

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 fluorescence spectroscopy, to track down the secret. The paintings were irradiated with X-rays. 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 Ferronnière”, 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 Mona Lisa for over four years, leaving the painting unfinished, according to texts from the Renaissance period.

Author: Philippe Walter, Centre de Recherche et de Restauration des Musées de France, Paris (France), mailto:philippe.walter@culture.gouv.fr

Title: Revealing the sfumato Technique of Leonardo da Vinci by X-Ray Fluorescence Spectroscopy

Angewandte Chemie International Edition 2010, 49, No. 35, 6125–6128, Permalink to the article: http://dx.doi.org/10.1002/anie.201001116

Philippe Walter | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht Individual Receptors Caught at Work
19.10.2017 | Julius-Maximilians-Universität Würzburg

nachricht Rapid environmental change makes species more vulnerable to extinction
19.10.2017 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>