A new study published in the journal Science Advances suggests humidity has a significant impact on the cadmium-based yellow paint used in a 1910 version of the work. (Owned by the Munch Museum in Oslo, the canvas was stolen in a devastating 2004 heist and only restored to its rightful place in 2006.) Scientists found that the pigment—employed in the Norwegian artist’s creation of The Scream’s central character, dramatic sunset and fjord—degraded due to moisture even in the dark, indicating that light isn’t a key factor in the colors’ deterioration.
“The museum is considering [whether] to apply the recommendations from this study in the future preservation and exhibition situation for The Scream,” Munch Museum paintings conservator Eva Storevik Tveit and conservation scientist Irina Sandu tell CNN’s Ashley Strickland via email. “As this painting is one of the most famous and also highly sensitive/fragile objects of our collection, a good scientific-based strategy for its preservation is fundamental.”
Per the study, the painting has spent much of the time following its recovery in storage, where it is housed under low lighting at 50 percent humidity and a temperature of roughly 64 degrees Fahrenheit.
Returned with water damage on its lower left corner, The Scream has been the subject of intense study in the years since the theft. As Sophie Haigney reported for New York Times in February, research conducted at the Scientific Analysis of Fine Art lab in New York City yielded evidence that the canvas’ yellow paints were degrading into tiny crystals of white chemical products.
“It turned out that rather than use pure cadmium sulfide as he should have done, apparently he also used a dirty version, a not very clean version that contained chlorides,” says Janssens. “I don’t think it was an intentional use—I think he just bought a not very high level of paint. This is 1910 and at that point the chemical industry producing the chemical pigments is there, but it doesn’t mean they have the quality control of today.”
Prior to the 1880s, painters used pigments derived from natural ingredients. But the rise of synthetic production added more variety and vibrancy to the range of paints available, enabling Impressionist and Expressionist artists like Munch and Vincent van Gogh to create bright, highly saturated canvases. Because the new synthetic paints weren’t tested for longevity, many late 19th-century and early 20th-century works have changed color over time.
To analyze the pigments used in the 1910 version of The Scream, researchers collected tiny flakes of paint from the thick layers of the fjord, mock-up paints with a similar chemical makeup to Munch’s and a sample of paint from one of Munch’s own paint tubes, reports CNN. (The Munch Museum houses more than 1,400 paint tubes once owned by the artist.)
The team then scientifically imaged the samples and exposed them to various levels of humidity, temperature and light. At 95 percent humidity, the samples degraded in both light and darkness, but at 45 percent humidity, they remained largely unaffected.
Armed with the knowledge that humidity—not light—is at the root of the painting’s troubles, the museum may be able to find a way to display it on a more permanent basis. The Scream will have to be sealed off from visitors, as the moisture produced by these individuals’ breath could raise humidity levels enough to cause damage, Janssens tells the Guardian.
Though the find may have implications for the conservation of works created with similar cadmium sulfide paints, chemist and lead author Letizia Monico of the Italian National Research Council in Perugia cautions that every painting is unique, and conservation plans must be determined on a case-by-case basis, according to Maria Temming of Science News.
“We strongly hope that in the future we will have the opportunity to study additional work of art by Munch and other artists contemporary to him,” Monico and heritage scientist Costanza Miliani tell CNN.