Leonardo's painting technique secrets uncovered

FLORENCE, Italy (Reuters) - Renaissance master Leonardo da Vinci avoided the palette and mixed colors directly on the canvas, Italian researchers said after they reconstructed his work step by step "as if watching him while he painted".

Using a scientific device to analyze Leonardo's "Madonna of the Yarnwinder" painting, researchers at the University of Florence said they were able to pinpoint virtually every stroke made by the famous Italian artist on the oil masterpiece.

That showed the Leonardo avoided mixing colors on a painter's palette like his contemporaries did. Instead, he applied thin layers of paint directly on the canvas in different colors one on top of the other to create a rich texture.

"That Leonardo used the "velature" technique is already known, he himself wrote that in a treaty, but for the first time we have managed to reconstruct his work step by step, like as if watching him while he painted," said Cecilia Frosinini, one of the researchers.

"We have been able to understand what type of painting materials he used, how many layers of colors were applied and in what thickness and sequence."

The painting scrutinized belongs to a collection in New York that has been dubbed the "Ex-Reford" version, the researchers said. It is the only one of several versions of the image credited to the artist himself, they said.

The researchers used a so-called "nuclear accelerator" device that launches particles at high speed to decipher the painting technique used by the artist.

Leonardo is considered among the greatest painters of all time, renowned -- among other things -- for his "Mona Lisa" and "The Last Supper" masterpieces that are among the most imitated and reproduced paintings in history.