Revealed: a previously unknown van Gogh

Vincent van Gogh is perhaps one of the best known of the post-impressionist painters.  The later years of his life were his most prolific, but the total number of his known works has just increased by one, as X-rays have recently revealed a previously hidden portrait.

It is well known that van Gogh re-used his canvases - as do many artists - reworking older compositions, or replacing abandoned works.  It is estimated that almost one-third of his early works are on such 'recycled' canvases.

"Grasgrond" ("Patch of Grass") was painted while van Gogh was in Paris, in 1887.  It's owners, the Kröller-Müller Museum in the Netherlands, had long been aware of there being a vague outline of a head, lurking beneath the grass.  Investigation of this area by conventional X-ray techniques have only ever revealed a partial, colourless impression of the under-painting.

Now this head has been fully revealed for the first time, by a team led by materials expert and art historian Joris Dik and chemist Koen Janssens.