Rembrandt Used Arsenic to Paint “The Night Watch”

Scientists researching Rembrandt’s The Night Watch revealed new insights into the centuries-old masterpiece. They found that Rembrandt used arsenic to mix a mysterious golden pigment that embellishes one of the painting’s protagonists. The research team comprises experts from the Rijksmuseum and the University of Amsterdam. They published their findings in a recent article in the Heritage Science journal.

Researchers mapped The Night Watch using macroscopic X-ray fluorescence imaging technology. This revealed the presence of arsenic sulfide minerals in the painting’s golden details. Rembrandt used the technique on the central-right figure, Lieutenant Willem Van Ruytenburch, whose embroidered coat and doublet sleeves are adorned with delicate golden threading. The research team initially assumed that Rembrandt used orpiment to mix yellow hues and realgar to mix red hues for these details on The Night Watch. Instead, they identified pararealgar and semi-amorphous pararealgar—both arsenic sulfide minerals—in this area of the painting. They determined that Rembrandt mixed the arsenic sulfide pigments with other pigments to achieve a convincing golden luster.

Rembrandt Knowingly Used Arsenic in The Night Watch

According to the research team, the presence of arsenic sulfides in The Night Watch indicates an intentional pigment combination by the artist. “Rembrandt clearly aimed for a bright orange tone with a high color strength that allowed him to create an illusion of the gold thread embroidery in Van Ruytenburch’s costume,” the study reads. The research team also compared The Night Watch to paint samples from other artists in the Rijksmuseum’s collection who were known to use arsenic sulfides. Notably, they found a similar mixture of pigments in a painting by Rembrandt’s contemporary, Willem Kalf.

The research team cited this discovery as “evidence that a variety of natural and artificial arsenic sulfides were manufactured and traded during Rembrandt’s time and were available in Amsterdam.” As such, the use of natural and artificial arsenic sulfides to create pigments was likely more common during the Dutch Golden Age than previously believed. Artists would have imported arsenic sulfide minerals to the Dutch Republic, which did not itself have adequate mining resources.

The Night Watch is the largest and most famous painting by Rembrandt van Rijn, Amsterdam’s preeminent portrait artist of the Dutch Golden Age. The painting was originally titled Civic Guardsmen of District II under the Command of Captain Frans Banninck Cocq. While it is now known by its more popular nickname, The Night Watch does not actually depict a nighttime event. The monumental canvas is notable for transforming a conventional group portrait—in this case, a company of Amsterdam civic guardsmen—into a dramatic and dynamic scene. Rembrandt was one of the first artists to paint every member of a group engaged in individualized action. This kicked off an exciting and enduring trend in 17th-century Dutch art.

In 2019, the Rijksmuseum in Amsterdam launched Operation Night Watch, a large-scale research project that remains ongoing. Experts aim to research and restore every inch of the canvas. So far, they have utilized a variety of noninvasive analytical imaging techniques on the painting. They have also studied paint samples to learn more about Rembrandt’s materials and techniques and how the painting might be best preserved for future generations. The Night Watch has undergone dozens of restorations over the centuries, but Operation Night Watch is the most extensive and advanced. The work is being carried out in a specially designed glass chamber located in the museum’s main gallery.