A routine cataloging of a Vincent van Gogh painting in the National Galleries in Scotland produced an unexpected discovery: a hidden self-portrait on the back of the canvas. The portrait was unveiled while conservationists conducted an X-ray analysis head of a peasant woman as part of a cataloging exercise in preparation for an upcoming exhibition. Once the exhibit opens, visitors can view the X-ray image through a custom-made light box in the center of the exhibit.
As I have previously reported, X-ray imaging techniques are a well-established tool for analyzing and restoring valuable paintings, as the higher frequency of the rays means they can penetrate paintings without damaging them. X-rays can show anything that has been painted on a canvas or where the artist may have altered the original vision.
For example Vermeer’s Girl reads a letter at an open window was first subjected to X-ray analysis in 1979, revealing the image of a Cupid lurking beneath the overpainting. And in 2020, a team of Dutch and French scientists used high-energy X-rays to unlock Rembrandt’s secret recipe for his famous impasto Technique believed to have been lost in history.
Last year we reported that researchers used infrared reflectography to see through the top layers of paint in the famous 18th-century portrait of French chemist Antoine Lavoisier. The resulting reflectogram showed evidence of carbon-based black underdrawing and dark, unclear shapes, indicating possible significant compositional changes. The team also used macro X-ray fluorescence imaging to map the distribution of elements in the color pigments – including the color used beneath the surface – to create detailed element maps for further study.
Nor is it the first time that a Van Gogh painting has undergone X-ray analysis. As early as 2008, European scientists used synchrotron radiation to reconstruct Van Gogh’s hidden portrait of a peasant woman. The artist, known for reusing his canvases, had painted over them when creating it in 1887 piece of lawn. The synchrotron radiation excites the atoms on the screen, which then themselves emit X-rays that can be picked up by a fluorescence detector. Each element in the painting has its own X-ray signature, allowing scientists to identify the distribution of each element in the many layers of paint.
Van Gogh was also known for reusing a canvas by painting on the reverse. As Van Gogh expert Martin Bailey writes in The Art Newspaper:
The Edinburgh painting is not van Gogh’s only double-sided canvas painting. In 1929, Dutch restorer Jan Cornelius Traas removed the cardboard backing from three Nuenen paintings, revealing hidden portraits on the reverse. And we can report that there have long been suspicions that there might be something on the hidden side head of a peasant woman.
Completed May 1885, head of a peasant woman is one of Van Gogh’s more modest efforts and was donated to the National Galleries in 1960 by an Edinburgh lawyer named Alexander Maitland. According to the museum, experts now believe it is part of a series of studies Van Gogh made in connection with a larger painting. The Potato Eaters (currently housed in the Vincent van Gogh Museum, Amsterdam), completed May 1885.
The museum’s conservators weren’t expecting much when they subjected the small painting to X-ray analysis. The resulting X-ray showed a portrait of a bearded sitter with a brimmed hat and a scarf loosely tied around her neck, who looked a lot like Van Gogh. The portrait was covered with layers of glue and cardboard, most likely applied in the early 20th century, possibly to make the painting more secure before framing it for an exhibition.
“Come on and lo and behold! We don’t see much of the peasant woman, but what we do have is the white lead, the much heavier pigment he used on his face, which shows up after the x-ray goes through the box,” Lesley Stevenson, senior painting conservator at the National Galleries of Scotland, opposite the Guardian. “Discovering a new work is extraordinary. Anything that gives us more information about the artist is a huge bonus and only shows the benefit of technological analysis that we can still find out new things.”
The next step is to figure out how to remove the layers of glue and cardboard covering the selfie without damaging the other painting. It is unclear what condition the self-portrait is in, more than a century later. “It’s like stepping into the unknown,” Stevenson told the Guardian. “The challenge is to remove the glue from the oil paint layers, exploiting the difference in solubility between animal glue and oil paint.”
Offer image by Neil Hanna