Underneath the surface Advanced synchrotron techniques for the study of 17th century oil paint in three dimensions

In this PhD thesis the composition, morphology and degradation of 17th century paints was studied using state of the art synchrotron radiation (SR) based X-ray methods. The degradation of arsenic sulfide pigments was revealed by studying model systems of different complexity, by use of SR-based XANES and X-ray transmission tomography. Furthermore, several paint samples of ‘The Night Watch’ by Rembrandt van Rijn were visualized and semi quantified with 2D microscale techniques and in 3D by introducing SR-based X-ray ptychography and fluorescence nano-tomography. This allowed us to better understand how Rembrandt created ‘The Night Watch’, which materials he used and what the current condition of the painting is. The results include the finding of unexpected arsenic sulfide pigment in ‘The Night Watch’, the discovery of an unknown lead-containing impregnation layer underneath the ground layer, and the use of different types of smalt pigment (cobalt colored glass) containing paints for different areas of the painting.