New X-ray imaging analyses of Rembrandt’s famous painting “The Night Watch” from 1642 indicate the presence of an unexpected lead layer, which may have been applied as a precautionary measure during the preparation of the canvas, according to a new research paper published in the journal Science Advances. The work is part of the Night Watch project carried out by the Rijksmuseum, which is the largest interdisciplinary research and conservation project for the renowned painting, dedicated to preserving the artwork in the long term.
Chemical and Mechanical Changes Over the Years
The painting “The Night Watch” is considered one of the largest surviving works by Rembrandt, particularly renowned for its masterful use of light and shadow. New X-ray imaging analyses reveal the presence of an unexpected lead layer, which may have been applied as a precautionary measure during the preparation of the canvas, according to a new research paper published in the journal Science Advances. The work is part of the Night Watch project carried out by the Rijksmuseum, which is the largest interdisciplinary research and conservation project for the renowned painting, dedicated to preserving the artwork in the long term.
Previous Analyses of Rembrandt’s Works
Previous analyses of Rembrandt’s works indicate his use of several pigments in his creations, including lead white, ochre, bone black, vermilion, madder red, azurite, ultramarine blue, madder yellow, and lead tin yellow, among others. The artist rarely used pure blue or green pigments, except for “Belshazzar’s Feast.”
The Unknown Lead Layer
Earlier this year, researchers in the Night Watch project discovered rare traces of a compound called lead formate in the painting. They scanned about half a square meter of the painting’s surface using powder diffraction X-ray imaging techniques (among others) and analyzed small fragments of the painting using micro X-ray synchrotron instruments. This revealed the presence of lead formate – which is surprising in itself – but the team also identified the presence of this formate in areas where there are no lead, white, or yellow pigments. It may be possible that lead formate disappears relatively quickly, which could explain why it has not been discovered in other Dutch artists’ paintings so far. But if this is the case, why did lead formate not disappear in “The Night Watch”? And where did it come from in the first place?
New 3D X-ray Imaging Techniques
According to the researchers, this is the first time that 3D X-ray imaging techniques have been used: fluorescence X-ray imaging and nano-tomography X-ray imaging on a small piece of canvas. Researchers point out that the analysis of historical works typically relies on two-dimensional imaging techniques (such as optical microscopy, scanning electron microscopy, and synchrotron radiation spectroscopy), which provide only partial information about the size, shape, and distribution of pigment particles below the visible surface.
The Unknown Lead Layer
3D techniques reveal more details about the presence of the unknown lead-containing layer, which lies directly beneath the ground layer. Researchers suggest that this could be due to the use of a lead compound added to the oil used to prepare the canvas as a drying agent – perhaps to protect the painting from the harmful effects of moisture. An adhesive is usually applied before the ground layer is placed.
The painting “The Night Watch” hung in the great hall of the Amsterdam training school for cavalry and faced the windows. Researchers note that since the Middle Ages, red lead in oil has been used to preserve stone, wood, and metal against moisture, citing a contemporary source that mentions the use of lead-rich oil instead of traditional glue to prevent the canvas from separating after years of exposure in humid environments. The newly discovered lead layer may be the reason for the unusual lead protrusions in areas of “The Night Watch” that do not contain other lead compounds in the paint. It is possible that the lead has migrated from the oil-prepared primary layer containing lead to the ground layer of the painting.
Source:
Science Advances, 2023. 10.1126/sciadv.adj9394
About the Author
Jennifer Ouellette is a senior writer at Ars Technica with a special focus on the intersection of science and culture, covering everything from physics and related interdisciplinary topics to her favorite movies and TV shows. Jennifer lives in Baltimore with her husband, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.
Leave a Reply