When studying The Night Watch with the stereomicroscope, the researchers discovered hundreds of microscopic ‘pimples’. These so-called lead soaps break through the paint surface and cause minuscule paint loss.
Lead soap formation is a well-known phenomenon in oil paintings, yet the researchers were surprised. Lead soaps usually occur when a lead-based primer has been used. But for The Night Watch, Rembrandt used a so-called quartz ground.
Researchers are now trying to find out why (so many) lead soaps are formed.
The microscopic ‘pimples’
05/04/2021
Research has revealed that Rembrandt paid incredible attention to the rendering of texture in the gold embroidery on Willem van Ruytenburch’s yellow coat. He used no less than 9 different pigments!
The lightest yellow was painted with lead white and lead-tin yellow, in a pastose, mayonnaise-like paint. The researchers were very surprised to find the element arsenic here, present in the pigments orpiment and orange realgar. Rembrandt used these highly toxic pigments to suggest the gold threads in the light shadow areas of the embroidery.
For the darker areas he used yellow ochre, and for the very darkest shadows, a mixture of red lake and a black. For the tiny blue accents between the gold threads, Rembrandt used the blue pigments, azurite and smalt.
