Researchers at Delft University of Technology (The Netherlands) and the University of Antwerp (Antwerp, Belgium) used synchrotron radiation-induced X-ray fluorescence spectroscopy to reveal a portrait of a woman by Vincent van Gogh beneath the paint of his 1887 "Patch of Grass." Van Gogh was known to paint over his work, perhaps as often as one third of the time. Behind the painting, done mostly in greens and blues, is a portrait of a woman, rendered in browns and reds. Synchrotron radiation-induced X-ray fluorescence spectroscopy measures chemicals in the pigments, and is said to be an improvement on X-ray radiography, which has been used to reveal concealed layers of other famous paintings. In this case, mercury and antimony were useful in revealing the woman?s face. Researchers said that the new technique is expected to pave the way for research into many other concealed paintings.
