The Night Watch, painted in 1642 and on view in the Rijksmuseum in Amsterdam, is considered Rembrandt’s most famous work. In new research, scientists found lead(II) formate — a compound very unusual for paintings — in several areas of The Night Watch.
Rembrandt van Rijn is one of the most innovative Dutch 17th-century painters.
The Night Watch, painted in 1642, today displayed in the Rijksmuseum, Amsterdam, is one of his most important masterpieces. It is the largest extant work of art he ever painted, measuring 3.79 by 4.53 m.
Rembrandt showcased his virtuosity, not only by achieving a bold composition with striking light and shadow effects, but also by his constant search for novelty in painting materials and techniques.
In 2019, a team of conservators, art historians and scientists launched the Operation Night Watch project to study The Night Watch.
“Lead pigments were widely used by Rembrandt,” said Université Paris-Saclay researcher Victor Gonzalez and colleagues.
“The most common was white lead, a mixture of lead carbonates hydrocerussite Pb3(CO3)2(OH)2 and cerussite PbCO3.”
“Lead is also present in other pigments, and their associated alteration products.”
“However, our discovery was more unusual: lead(II) formate Pb(HCOO)2, a compound that has never before been found in historical oil paintings.”
“Lead formate, the lead salt of formic acid, was found in several areas of The Night Watch — sometimes together with plumbonacrite Pb5(CO3)3O(OH)2, another rare lead compound.”
To investigate the chemical origin of lead formate, the authors created model paint layers using old recipes.
For example, siccative oil was prepared by heating linseed oil, the most common binding agent for paints at the time, with lead oxide PbO.
“Lead oxide is a metallic dryer, causing paints to harden more quickly,” the researchers said.
“We showed that PbO in oil paint can react to form lead formate.”
“Even though no crystalline PbO was…
Read the full article here