BRITAIN:A Vincent van Gogh portrait of a woman that was painted over and hidden by the artist has been revealed in extraordinary detail by experts using a new X-ray technique.
The peasant woman's face emerged from the centre of the work, Patch of Grass, completed by van Gogh in Paris in 1887 and now owned by the Kroller-Muller Museum in the Netherlands.
It is well known that van Gogh often painted over his older works, and experts estimate that about one-third of the Dutch artist's early pictures conceal other compositions. Previous research had discovered the vague outline of a head behind the Patch of Grass painting.
But the dramatic detail of the hidden portrait only came to light through a technique known as X-ray fluorescence spectroscopy, which had never before been applied to a painting. Over a period of two days, scientists scanned the picture with a pencil-thin beam of X-rays generated by a synchrotron, a machine that accelerates subatomic particles.
The powerful bombardment caused atoms in the picture's layers of paint to release "fluorescent" X-rays of their own which could be used to map the chemicals they originated from.
In this way the scientists, led by Dr Joris Dik, from Delft University of Technology in the Netherlands, and Prof Koen Janssens from the University of Antwerp, in Belgium, were able to reconstruct the hidden portrait in unparalleled detail.
Elements from specific paint pigments allowed a "colour photo" of the concealed work to be produced. The woman's head, which is looking slightly to the left, fills a square area measuring 17.5 by 17.5cm.
The scientists wrote in the journal Analytical Chemistry: "Van Gogh would often re-use the canvas of an abandoned painting and paint a new or modified composition on top.
"These hidden paintings offer a unique and intimate insight into the genesis of his works. Yet current museum-based imaging tools are unable to properly visualise many of these hidden images."
The portrait may have been part of an extensive series of heads painted by van Gogh while staying in the Dutch village of Nuenen, said the researchers.
Between October 1884 and May 1885 he painted the heads of peasant models in the dark settings of their huts in the vicinity of the village. "Van Gogh did not intend to render lifelike portraits but rather meant to train his control over form, colour and light effects," the scientists wrote.
"More specifically, the present head must belong to a smaller group of studies that Vincent gave to his brother Theo in Paris, as mentioned in his letters."
- (PA)