X-rays unravel mysterious degradation of a Van Gogh painting

An article published recently in the magazine Analytical Chemistry describes a previously unknown and never before researched degradation process of cadmium yellow oil paint. This degradation process was found on parts of Vincent van Gogh’s painting Flowers in a blue vase, which is in the collection of the Kröller-Müller Museum. During the conservation treatment of the painting in 2009, an unusual grey, non-transparent crust was discovered on the cadmium yellow sections. The removal of this crust and the highly discoloured varnish layer proved impossible without damaging the extremely fragile underlying cadmium yellow paint. This dilemma was partly the reason for the research into this unknown form of degradation of cadmium yellow oil paint.

The research was conducted by an international interdisciplinary team of scientists, consisting of chemists from the University of Antwerp, the Delft University of Technology, the Laboratoire du Centre de Recherche et de Restauration des Musées de France in Paris, the European Synchrotron Radiation Facility in Grenoble, the Deutsches Elektronen-Synchrotron in Hamburg and conservators from the Kröller-Müller Museum.

This interdisciplinary research, which combined the expertise of chemists and conservators, is extremely important for the understanding and conservation of our cultural heritage. It helps conservators to make better decisions concerning the conservation of paintings with this kind of complex and still relatively unknown degradation processes.