Deep in the storage depot of the Royal Museum of Fine Arts Antwerp in Belgium lay an ancient painting.

Believed for generations to be a copy of "The Mocking of Samson" by famous Dutch artist Jan Steen, it had hung in storage, neglected, for decades.

The picture, which depicts a scene from the biblical story of Samson and Delilah, had once been considered genuine. But in the early 20th century, the museum declared the signature to be fake and the work was re-attributed to the renowned Flemish copyist Jacques Ignatius de Roore. The whereabouts of Steen’s original work remained unknown.

Everything changed in 2017 when the Mauritshuis museum in The Hague, the Netherlands, was planning a new Jan Steen exhibition. Intrigued by the painting held in Antwerp, curator Ariane Van Suchtelen and paintings conservator Sabrina Meloni travelled to the Belgian art museum to examine it.

On first inspection, it did not look like a copy: the style was too similar to the great painter’s other works. And remarkably, the signature looked original too.

Meloni had an optical microscope that could magnify the painting by 400 times. But she knew this would not be enough. To discover if this really was an original, she needed to forensically compare chemical pigments in the paint to those in other Jan Steen originals. And for that, she needed a very powerful microscope.

Scanning electron microscope

The Mauritshuis contacted the Shell Technology Centre in Amsterdam, which had a scanning electron microscope. This microscope scans a sample with a beam of electrons, providing information on the object’s surface, structure and composition.

"To confirm whether the artwork was genuine we needed to analyse the chemical elements in the paint pigments," says Ralph Haswell, a Principal Research Scientist at the technology centre. "With a scanning electron microscope we can look at the sample at a 1,000 times magnification so we really can see all the individual pigment particles."

These microscopes are a crucial part of Shell’s work with catalysts. A catalyst is a substance which is used to increase the speed of a chemical reaction and they are found in almost every chemical and refinery process at Shell. In total, Shell employs around 1,600 different types of catalyst. "Without them we cannot run the refineries or chemical plants, the processes would be too slow," explains Haswell.

The microscope is required to examine the composition of the catalysts to identify ways to improve and enhance them, a particular specialism of the technology centre.

Testing of Samson

Meloni took a few paint samples, each the size of a pin head, from different parts of the painting. She then mounted them into small blocks of resin that could be studied under the scanning electron microscope.

In one of the samples, Haswell and Meloni found "green earth", a pigment not extensively used in 17th century paintings, but encountered a lot on the late works of Jan Steen. They also found the presence of a double-ground layer, or base layer, which is also seen in other late works of Steen.

The painting was indeed real. "We found some really nice indicators that allowed us to place the painting in a group of works created by Steen in the 1670s," says Meloni.

Examining the painting also revealed the presence of pentimenti — an Italian word for visible traces of changes made by the artists during the painting process. Art historians see pentimenti as evidence that the artist had altered his work during the painting process.

"If you are copying a painting then you just look at it and make a copy," Meloni explains. "But if the painting is a genuine work of art then you’ll see evidence that the painter has changed his mind while painting."

The condition of the painting was particularly striking. "It was a bit dirty and had some layers of dark varnish that needed removing, but apart from that it was quite untouched," she says. One of the paint layers even contained a long hair. "Of course, you can never say for certain, but Jan Steen’s self-portraits do show him to have long, dark, wavy hair," adds Meloni. "I like to think that it comes from him."

Jan Steen (1626 – 1679)

people in a room

Jan Havickszoon Steen is considered to be one of the leading painters of the Dutch Golden Age alongside Rembrandt, Vermeer and Hals. Famous for his witty, lively and often chaotic portrayals of human interactions, his work gave rise to the Dutch phrase "a Jan Steen household", used to indicate a particularly messy or disordered house. One such example is the painting on the left, "As the Old Sing, So Pipe the Young". Steen's paintings are the subject of an exhibition at the Mauritshuis that features "The Mocking of Samson".

Header image: Marya Albrecht and Sabrina Meloni examine "The Mocking of Samson" from the KMSKA. Photo by Ivo Hoekstra

Panel image: Jan Steen, 'As the Old Sing, So Pipe the Young', c.1668 – 1670, Mauritshuis, The Hague

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