Using a new technique to look beneath Vincent van Gogh's "Patch of Grass" a new painting was discovered. Scientists knew something was there, van Gogh was well known for painting over previous art.
"Patch of Grass" painted in Paris in 1887 used mostly blues and greens hides a portrait of a woman painted in browns and reds.
The painting is owned by the Kroller-Muller Museum.
Scientists use "synchrotron radiation induced X-ray fluorescence spectroscopy" to reveal hidden artwork under famous paintings. This method uses chemicals in the paint pigments, mercury and the element antimony are key chemicals, to see past the top layers.
The research on this painting by van Gogh is being conducted by Delft University of Technology in the the Netherlands and the University of Antwerp in Belgium. Other institutions are helping in the process.
Researchers are studying the evolution of von Gogh's work.