In 2008, researchers at the HASYLAB subjected van Gogh’s painting Patch of Grass to XRF spectroscopic analysis in the hopes of imaging a painting believed to be hidden under Patch of Grass. The XRF utilized microfluorescence beamline L radiation; a second-generation synchrotron light source. The scan was conducted over 2 days with 0.5 mm2 pixel resolution. The composition of the underlying pigments was analyzed and using imaging software, the researchers were able to image a women’s face. The image of the woman’s face is believed to be an early draft of the painting Peasant Woman by van Gogh and van Gogh simply “recycled” the canvas when he painted Patch of Grass.
 Hamburg Synchrotron Radiation Laboratory
“Reprinted with permission from (Visualization of a Lost Painting by Vincent van Gogh Using Synchrotron Radiation Based X-ray Fluorescence Elemental Mapping. Joris Dik, Koen Janssens, Geert Van Der Snickt, Luuk van der Loeff, Karen Rickers, and Marine Cotte Anal. Chem. 2008 80 (16), 6436-6442) American Chemical Society.