PARIS ? Mona Lisa's celebrated shadows around her eyes and mouth were created by Leonardo da Vinci through layers of different paints, according to a groundbreaking study published Tuesday.

Using a technique known as sfumato, which overlays translucent layers of color to create perceptions of depth, volume and form, da Vinci first applied paint containing manganese on the celebrated painting, the study published in the periodical Applied Optics reported.

That was followed by a second layer containing a mix of vermillion and lead, in a technique widely used by Italian painters of the period, according to the study's author Mady Elias.

The analysis of the layers was done using a multi-spectral camera that can measure 100 million luminous spectrums in as many points on the painting.

"This is the first time that an accounting of luminous fluxes in the material has been applied to art," said Elias, a researcher at the Paris-based National Center for Scientific Research, of a technique previously used only in atmospheric and oceanographic sciences.

The Mona Lisa hangs in the Louvre art museum in Paris.