The second phase of the Rijksmuseum’s Operation Night Watch, the largest research and restoration project ever undertaken for Rembrandt’s 1642 masterpiece – The Night Watch – is in motion.
On Tuesday, a team of eight restorers at Amsterdam’s national museum started removing the varnish from the oil painting, measuring 363 x 437 cm. The move follows the first stage of the operation: five years of investigation and analysis using advanced techniques including digital imaging, scientific and material-technical research, computer science, and artificial intelligence.
The restorers are working in a specially designed glass chamber in the Rijksmuseum’s Gallery of Honor in full view of the public
“After years of careful research, we’ve developed a focused plan to treat the varnish and paint layers of The Night Watch,” the team said in a video. “For the removal of the old varnish, we’re using a special technique: non-woven tissue prepared with a measured amount of solvent. The advantage of this technique is that less mechanical action is required on the painting. You place the tissue on the surface and for [60 seconds] let the solvent do its work. Any remaining varnish on the surface of the painting will be removed under microscope with cotton swabs and other methods.”
They said the paint will look “very grey and dull” during the restoration but will regain its vigor when the new varnish is applied. Removing the varnish, which was applied during the last restoration of the painting in 1975-76, and adding a new layer will “optimally preserve the painting for the future,” the museum said in a statement. This process follows trials on other paintings and tests on The Night Watch itself.
“The start of the restoration is thrilling. Removing the varnish will reveal The Night Watch‘s eventful history,” Taco Dibbits, the general director of the Rijksmuseum, said. “It will be a unique experience for the public to follow this process up close.”
In July, during the first phase of Operation Night Watch – which began in 2019 – chemists from Holland’s University of Amsterdam (UvA) worked out how Rembrandt managed to embellish the painting with striking golden detail.
They used high-tech spectroscopic technology to identify the presence of (yellow) pararealgar and (orange/red) semi-amorphous pararealgar pigments in minute detail in the famous artwork. The research team concluded that the Dutch artist intentionally mixed these particular arsenic sulfide pigments with other pigments to create the golden sheen.
Rembrandt used the technique to paint the golden threading in the embroidered buff coat and double sleeves worn by one of painting’s two protagonists, Lieutenant Willem van Ruytenburch.
The study was published in Heritage Science, a journal of peer-reviewed research, by Fréderique Broers and Nouchka de Keyser, PhD students at UvA’s Van ’t Hoff Institute for Molecular Sciences, and also researchers at the Rijksmuseum.
Other secrets were unearthed during the research, including the presence of arsenic and sulfur in Van Ruytenburch’s clothing following an X-ray fluorescence (MA-XRF) scan. As a result, researchers presume Rembrandt used arsenic sulfide pigments realgar [red] and orpiment [yellow].
Operation Night Watch is a collaboration between several institutions including the Cultural Heritage Agency of the Netherlands (RCE), the Delft University of Technology (TU Delft), the Amsterdam University Medical Centers (AUMC), and the National Gallery of Art, Washington D.C.
