Hidden van Gogh painting unveiled for first time

AMSTERDAM, Netherlands (AP) -- A team of European scientists unveiled on Wednesday a new method for extracting images hidden under old masters' paintings, recreating a color portrait of a woman's face unseen since Vincent van Gogh painted over it in 1887.

In this composite photo from the Delft University of Technology, the hidden portrait is seen.

For years, art historians have been using x-rays to probe artworks hidden underneath other paintings, a technique resulting in a fuzzy, black-and-white image.

But Joris Dik, a materials scientist from Delft University, and Koen Janssens, a chemist from the University of Antwerp in Belgium, combined science and art to engineer a new method of visualizing hidden paintings, using high-intensity x-rays and an intimate knowledge of old pigments.

The pair used the new approach on "Patch of Grass," a small oil study of a field that Van Gogh painted in Paris while living with his brother Theo, who supported him.

While not exact in every detail, the image produced is a woman's head that may be the same model Van Gogh painted in a series of portraits leading up to the 1885 masterpiece "The Potato Eaters."

The new method will allow art historians to obtain higher quality and more detailed images underlying old masterpieces. In Van Gogh's case, it could reveal details of works that were painted over. For other works, it could provide new insights into the studies that the artist built a painting on.

Dik and Janssens used high-intensity x-rays from a particle accelerator in Hamburg, Germany to compile a two-dimensional map of the metallic atoms on the painting beneath "Patch of Grass," which is part of the large Van Gogh collection in the Kroller-Muller Museum in the Netherlands.