Mysterious Rembrandt:
X-ray analysis revealed the details of the hidden picture

Sophisticated x-ray technology will help reveal the secrets of Rembrandt’s 380-year-old masterpiece. Under the painting “Old Man in Military Costume” (Old Man in Military Costume), painted by a Dutch artist in 1630-31, studies conducted several years ago found another portrait that, for the then existing technologies, was barely visible. For quite some time, art critics have been puzzling over the question of who is depicted in the "repainted" picture.

Photo: Brookhaven National Laboratory, bnl.gov

An international team of scientists tried to answer this question using the DORIS X-ray source of the German Synchrotron Center (DESY), Hamburg, and the National Synchrotron Source (NSLS) from Brookhaven National Laboratory (BNL) in the United States, as well as mobile X-ray scanners. The results of the study are published in the Journal of Analytical Atomic Spectrometry (JAAS) of the British Royal Chemical Society.

“Our experiments show a good opportunity to reveal the hidden details of the picture,” said the first author Matthias Alfeld from the University of Antwerp (Belgium). “Compared to other methods, x-ray studies are currently the best way to view the“ hidden ”picture.”

Scientists used Macro-X-ray fluorescence analysis (MA-XRF), a relatively new method for studying two-layer painting. Under intense x-rays, various pigments glow in a certain way. This allows researchers to determine the chemical composition of the upper and lower layers. When scanning the entire picture with an X-ray, you can see the bottom layer without destroying the canvas itself.

"The old man in a military suit" was investigated earlier, using infrared, neutron and ordinary x-ray radiation, but it was not possible to obtain a satisfactory result. “The problem with Rembrandt’s painting is that he used the same paint with the same chemical composition for both the base and the final painting,” explained Karen Appel from DESY, who also participated in a similar study of the work of Vincent van Gogh. “Van Gogh used various pigments, which makes the study of his“ hidden ”paintings much easier for researchers.”

The team of scientists decided to try out various methods for analyzing fluorescence fluoroscopy: using a mobile X-ray scanner, DORIS and NSLS. In order to avoid the time-consuming transportation of the original painting, which is located in the Paul Getty Museum in Los Angeles, museum intern Andrea Sartorius created an experimental layout. To do this, she used a paint with the same chemical composition as that of Rembrandt van Rijn, and painted two paintings on canvas: a portrait and a copy of The Old Man in a Military Suit from above. “This is the first time that the picture has been fully reproduced specifically for the tests,” Alfeld said.

The layout was used to determine the most promising method of studying the original. He also helped researchers explore the likelihood of success analyzing other, earlier Rembrandt paintings. “We have created a model that allows you to test and compare all types of analysis,” said Joris Dik, a professor at Delft University of Technology and one of the co-authors of the article. “This is an extremely valuable experience, both for us and for museums.”

Using x-rays, scientists excited fluorescence from elements such as calcium, iron, mercury, and lead. The study shows that macro-x-ray fluorescence analysis (MA-XRF) provides a much clearer image of the latent picture than all previously known methods. Mercury cinnabar and lead of white pigments in the face area give a particularly good image of a hidden portrait. The best results were obtained using large sources of synchrotron radiation - DORIS and NSLS. Nevertheless, mobile technologies are also quite effective, so this kind of research can do without the complicated transportation of original paintings to research centers. “We are confident that in this way it will be possible to“ expose ”all of Rembrandt’s hidden secret paintings,” said Koen Janssens, a professor at the University of Antwerp and an expert in X-ray analysis.

Karen Trentelman, director of research at the Getty Institute in Los Angeles, said: “Successfully completing the preliminary research on the painting’s layout was the first important step to determine the best approach to more thorough study of the original painting in the near future.”

The DESY Institute in Hamburg is Germany’s leading research center and one of the best in the world. Along with the Zeuthen Center near Berlin, he specializes in the design, construction and operation of large particle accelerators to study the structure of matter. DESY conducts research in the field of photon sciences and particle physics - this combination is unique in Europe.

Anna Sidorova