PARIS.- 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.
Collector members of the ARTKABINETT social network have visited the masterpiece many times. One is astounded by the face's ability to follow movement and captivate attention.
This investigation shows the composition and thickness of each layer of material laid down by the painter. The results reveal that, in the case of glazes(1), thin layers of 1 to 2 micrometers have been applied. The study, led by the team of Philippe Walter, of the Laboratoire du Centre de Recherche et de Restauration des MusÈes de Franceî (LC2RMF, CNRS/MinistËre de la culture et de la communication), with the collaboration of the European Synchrotron Radiation Facility (ESRF) and the support of the Louvre Museum, is published the 15 of July 2010 in the journal Angewandte Chemie International Edition.
Leonardo Da Vinci's paintings fascinate, partly due to a range of subtle optical effects that blur outlines, soften transitions and blend shadows like smoke.
Known as "sfumato", this technique is not only the result of the genius of the artist but also of technical innovations at the beginning of the 16th century.
Minute observations, optical measurements and reconstitutions have already described the sfumato, but new analysis can confirm the procedure of this technique, especially related to how the gradation is done.
For the first time, Philippe Walter (LC2RMF) and his team, in collaboration with the ESRF and the Louvre Museum, have brought new insight on the sfumato thanks to a quantitative chemical study of the different painted layers.
Seven paintings of Leonardo Da Vinci have been analysed without extraction, directly in the rooms of the Louvre Museum (Virgin of the Rocks, Mona Lisa, Saint John the Baptist, Annunciation, Bacchus, Belle FerronniËre, Saint Anne, the Virgin and the Child).
The scientists concentrated on the study of the faces because they have the characteristics of the sfumato. They used a technique called X-ray fluorescence(2) to determine the composition and thickness of each layer in nine faces (including Mona Lisa's) painted by Da Vinci throughout 40 years of career.
The scientists have also found different recipes used by Da Vinci to do the shadows on the faces. These recipes are characterized by a technique (the use of glaze layers or a very thin paint) and by the nature of the pigments or additives. In the case of the glazes, thin layers of 1 to 2 micrometres were applied to obtain a total thickness of no more than 30 to 40 micrometres. The results obtained in this study help to understand Da Vinci's search towards making his art look alive.
There are two classic styles of painting which we associate with the Old Masters, sfumato and chiaroscuro, and they are as alike as cheese and chalk. But we still manage to confuse them, and which artists made use of which styles.
Sfmuato and Leonardo da Vinci
Sfumato refers to the subtle gradation of tone which was used to obscure sharp edges and create a synergy between lights and shadows in a painting. As Ernst Gombrich2, one of the twentieth-centuries most famous art historians, explains: "This is Leonardo's famous invention - the blurred outline and mellowed colours that allow one form to merge with another and always leave something to our imagination."
Leonardo da Vinci used the technique with great mastery; in his painting the Mona Lisa those enigmatic aspects of her smile have been achieved precisely by this method, and we are left to fill in the detail.
How, exactly, did Leonardo achieve this effect? For the painting as a whole he selected a range of unifying midtones, especially the blues, greens, and earths, which had similar levels of saturation.
By avoiding the most luminous of colors for his brights, which could break the unity, the midtones thus created a subdued flavor to the picture.
Leonardo da Vinci is quoted as saying "[w]hen you want to make a portrait, do it in dull weather, or as evening falls."
Sfumato takes us one stage further though, away from the focal point of the picture, the midtones blend into shadow, color dissipates into monochromatic darks, much the same as you get on a photographic image with a tight focal range.
Sfumato makes an excellent choice if your portrait sitter is embarrassed by wrinkles!
