Researchers from the University of Amsterdam (UvA) have used advanced spectroscopic techniques to identify the presence of pararealgar (yellow and orange/red) pigments in Rembrandt’s The Night Watch painting, explaining how he achieved intricate golden details. The team, led by Ph.D. students Fréderique Broers and Nouchka de Keyser, concluded that Rembrandt mixed these arsenic sulfide pigments with others to create the golden sheen. The study was published in Heritage Science journal.
Rembrandt utilized this technique for the golden threading on Lieutenant Willem van Ruytenburch’s embroidered buff coat and double sleeves in The Night Watch. This discovery is part of the Operation Night Watch project, which began in 2019. Researchers also found arsenic and sulfur in Van Ruytenburch’s clothing through an X-ray fluorescence (MA-XRF) scan, suggesting Rembrandt used realgar (red) and orpiment (yellow) arsenic sulfide pigments.
Historical records support this finding and suggest a wider range of such materials were available to artists in 17th century Amsterdam than previously thought.
Source: https://www.artnews.com/art-news/news/dutch-chemists-work-out-how-rembrandt-made-gold-paint-in-the-night-watch-1234712914/