Rembrandt and/ or studio, Saul and David, c.1655: revealing the curtain using cross-section analyses and X-ray fluorescence imaging

Recent technical investigation of a late Rembrandt painting - Saul and David, c.1655 - from the collection of the Mauritshuis in The Hague has revealed important new information regarding the picture’s condition and original appearance. As already known, at some point in the past, the two figures were cut apart and reassembled. At the same time a large piece of missing canvas was replaced above the head of David and narrow strips were added along the upper, right and lower edges. Moreover, it has now been established that the painting consists of ten separate pieces of canvas and that a strip of canvas is also missing along the vertical join between the figures of Saul and David, in addition to along the bottom edge. Much uncertainty also surrounded the authenticity of the curtain and the extent of overpaint in the background between the two figures. In this regard, traditional imaging techniques, such as X-radiography and infrared reflectography (IRR), gave little information about the condition of the paint layers. Subsequent micro-analyses of carefully selected paint samples demonstrated that a curtain is indeed original to the painting and that the original curtain paint layer contains smalt, a pigment made of ground cobalt glass, which is absent in the overpaint. Recent collaboration with the universities of Antwerp and Delft involving X-ray fluorescence (XRF) imaging using a novel, mobile XRF scanner, provided elemental distribution maps of the curtain area between the two figures. The cobalt, nickel, arsenic and potassium distribution maps generated from elements in the smalt provide, for the first time, an image of the original curtain hidden below the muddy overpaint and yellowed varnish