Amsterdam - A team of European scientists has exposed a fresh technique of extracting images hidden under Old Master paintings without injuring them, recreating a color portrayal of a woman's face hidden since Vincent van Gogh painted over it in 1887.

While not precise in every feature, the image produced displays a woman's head that a van Gogh specialist said might be that of the sample in a series of portraits chief up to the 1885 masterpiece The Potato Eaters. Van Gogh often used again canvas to save money, either painting on the back or over the top of accessible paintings.

Joris Dik, a materials scientist from Delft University, and Koen Janssens, a chemist from the University of Antwerp, joined science and art to engineer a fresh technique of looking at unseen paintings, using high-intensity x-rays and an intimate knowledge of old pigments.