Researchers have decided to get personal with Mona Lisa–by irradiating her face. In a study recently published in Angewandte Chemie, researchers trucked around the Louvre to look at nine faces painted by Leonardo Da Vinci with a portable X-ray machine.
Their particular technique, as reported by the BBC, is called X-ray fluorescence (XRF) and is a way to uncover the layers of paint without damaging the paintings. By looking at this layering, they learned more about Da Vinci’s brush strokes and a technique called sfumato, which he used to hide transitions between dark and light areas and to create realistic shading.
The Da Vinci researchers aren’t the only X-ray art historians. Another recently published study looked at “Mayan blue”–a long lasting pigment made by the civilization that lived in Central American from 2500 BC to the 1600s.