A French scientist named Pascal Cotte used a new method of light based layer analysis called the Layer Amplification Method to examine what lies beneath the paint:
The method involves a multispectral camera projecting intense lights on to the painting while measuring the reflections, helping look for what happened between the paint layers.
Cotte believes one of the hidden portraits is the actual painting of Lisa del Giocondo, the woman thought to be portrayed in the Mona Lisa.
via Neatorama
