"Long before it's in the papers"
January 28, 2015


Scientists attack mysteries behind Mona Lisa

Sept. 26, 2006
Courtesy National Research Council
and World Science staff

For five cen­turies she has given us mys­te­ri­ous looks. Now re­search­ers claim to have cracked some enig­mas of the paint­ing itself: us­ing a colour la­ser scan­ning sys­tem, sci­en­tists say they have re­vealed some se­crets be­hind the world’s most fa­mous paint­ing.

Sci­en­tist Marc Ri­oux of the Na­tion­al Re­search Coun­cil ex­am­ines a vir­tu­al 3-D mod­el of the paint­ing (Cour­te­sy NRC)

Re­search­ers from Canada’s Na­tion­al Re­search Coun­cil, in Ot­ta­wa, trav­eled to Par­is to scan Le­o­nar­do da Vin­ci’s Mo­na Li­sa.

The technology, ca­pa­ble of scan­ning 3D im­ages at a depth res­o­lu­tion of 10 micro-meters, or about one tenth the width of a hu­man hair, has pro­vid­ed unique in­sights that will help cu­ra­tors and con­ser­va­tors in on­go­ing stud­ies of the mas­ter­piece, re­search­ers said. 

It “has not on­ly helped to fur­ther our un­der­stand­ing of Leonar­do’s sfu­ma­to tech­nique of soft, heav­i­ly shad­ed mod­el­ing,” said Hen­ri Loyrette, Di­rec­tor of the Lou­vre Mu­seum in Par­is, which com­mis­sioned the stu­dy. It “will al­so help to ad­dress the conserva­tion and de­te­ri­o­ra­tion con­cerns we have.” 

The scan­ner is a ver­sion of tech­nol­o­gy Amer­i­can as­tro­nauts used ear­li­er this month to check the space shut­tle for dam­age be­fore it re­turned to Earth. 

Da Vin­ci called his soft shad­ing tech­nique sfu­ma­to, from the Ital­ian word for smoke. The study re­vealed how he ap­plied the tech­nique to the Mo­na Li­sa, said the coun­cil’s John Tay­lor, who co­or­di­nat­ed the stu­dy. 

With the scan­ner’s high res­o­lu­tion, the pat­tern of brush strokes on a typ­i­cal paint­ing stands out like rip­ples on the sea, he added. But with this work “we don’t see any signs of brush stroke de­tail. It’s ex­treme­ly thin­ly paint­ed and ex­treme­ly flat, and yet the de­tails of the curls of hair, for ex­am­ple are ex­treme­ly dis­tinct. So, the tech­nique is un­like an­ything we’ve ev­er seen be­fore. Leonardo was in a league of his own.”

Al­though it’s thought he may have used his fin­gers to paint, Tay­lor said there are no signs of fin­ger­prints on the Mo­na Li­sa, as ap­pear on oth­er da Vin­ci paint­ings. 

Art ex­perts say the sfu­ma­to tech­nique in­volved over­lay­ing trans­lu­cent lay­ers of col­or to cre­ate the per­cep­tion of depth, vol­ume and form. “With the scan­ning we’ve dem­on­strat­ed that the darker ar­eas, such as the eyes, are in­deed thicker in­di­cat­ing that they are com­posed of a suc­ces­sion of thin­ly ap­plied glaze lay­ers,” said coun­cil sci­entist François Blais.

But how the Ren­ais­sance mas­ter ac­tu­al­ly ap­plied his lay­ers of pig­ment and oil me­di­um is still a mys­ter­y, said the re­search­ers, who al­so found that the work shows no signs of de­te­ri­o­ra­ting.

The re­sults ap­pear in a book, Au coeur de la Jo­conde, pub­lished in French by Gal­li­mard Edi­tions and Mo­na Li­sa: In­side the Paint­ing pub­lished in Eng­lish by Har­ry N. Abrams Inc. In com­ing months the coun­cil will con­tin­ue its re­search, in tan­dem with the Cen­ter for Re­search and Restora­tion of the Mu­se­ums of France, ac­cord­ing to coun­cil of­fi­cials.

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Apparel and Accessories at National Geographic National Geographic Books

For five centuries she’s been the source of endless real and fictional mysteries, from the magic of her eyes—always seeming to follow the viewer—to the enigma of her smile, and author Dan Brown’s blockbuster The da Vinci Code. Now, using a colour laser scanning system, scientists say they have revealed some secrets behind the world’s most famous painting. Researchers from Canada’s National Research Council, in Ottawa, traveled to Paris to scan the picture. Capable of scanning 3D images at a depth resolution of 10 micro-meters, or about one tenth the width of a human hair, the technology has provided unique views of the portrait that will help curators and conservators in ongoing studies of the masterpiece, researchers said. It “has not only helped to further our understanding of Leonardo’s sfumato technique of soft, heavily shaded modeling, but will also help to address the conservation and deterioration concerns we have,” said Henri Loyrette, Director of the Musée du Louvre in Paris, which commissioned the study. The scanner is a version of technology American astronauts used earlier this month to check the space shuttle for damage before it returned to Earth. Leonardo da Vinci called his soft shading technique sfumato, from the Italian word for smoke. The study revealed how he actually applied the technique to the Mona Lisa, said the council’s John Taylor, who coordinated the study. With the high-resolution of the scanner, the relief pattern of brush strokes on a typical painting appear like ripples on the sea, he added. “We don’t see any signs of brush stroke detail,” he continued. “It’s extremely thinly painted and extremely flat, and yet the details of the curls of hair, for example are extremely distinct. So, the technique is unlike anything we’ve ever seen before. Leonardo was in a league of his own.” Although it’s thought he may have used his fingers to paint, Taylor said there are no signs of fingerprints on the Mona Lisa, as appear on other da Vinci paintings. Art experts say the sfumato technique involved overlaying translucent layers of color to create the perception of depth, volume, form and lighter or darker areas. “With the scanning we’ve demonstrated that the darker areas, such as the eyes, are indeed thicker indicating that they are composed of a succession of thinly applied glaze layers,” said council scientist François Blais. But how the Renaissance master actually applied his layers of pigment and oil medium is still a mystery, the researchers said. The researchers also concluded that the work is not deteriorating. The results appear in a book, Au coeur de la Joconde, published in French by Gallimard Editions and Mona Lisa: Inside the Painting published in English by Harry N. Abrams Inc. In coming months the council will continue its research, in collaboration with the Center for Research and Restorations of the Museums of France, according to council officials.