Moisture, not light, explains why Munch’s “The Scream” is deteriorating

Discoloration and damage to cadmium yellow paint is mainly from water, a study finds

Image: Munch Museum, Oslo / Creative Commons
Moisture is the main reason that vivid yellow paint on Edvard Munch’s 1910 version of “The Scream” is fading and flaking off, a new study finds. That insight could help preserve the painting’s delicate composition.

MARIA TEMMING
ScienceNews

New insight into paint preservation could help “The Scream” show its face in public again.

Edvard Munch’s 1910 version of this iconic artwork has rarely been displayed since 2006, because the painting’s cadmium sulfide pigments are so fragile. Cadmium yellow brushstrokes in the sky and central figure have faded to off-white, and thick paint in the lake is flaking off. To prevent further decay, the Munch Museum in Oslo almost always keeps “The Scream” in storage, under carefully controlled lighting and about 50% humidity.

A chemical analysis of the painting shows that moisture is the main reason for the deterioration, while light plays only a minor role. Chemist Letizia Monico and her colleagues at the Italian National Research Council in Perugia reported this on May 15 in Science Advances online.

Researchers analyzed microscopic flakes of paint from “The Scream” along with paint samples with similar chemical composition that were artificially aged in the lab.

X-ray probes of the paint samples revealed cadmium sulfate, a breakdown product of cadmium sulfide, in paint flecks from “The Scream.” Cadmium sulfate also showed up in artificially aged paints that were exposed to at least 95% humidity in both light and darkness, but similar samples exposed to light in 45% humidity didn’t show signs of decay. This suggests that moisture is the main culprit in aging “The Scream,” and that although the painting may be fine under normal lighting, it should be kept at 45% humidity or below.

This new understanding of the artwork may inform the preservation of other paintings by Munch’s contemporaries, such as Henri Matisse and Vincent van Gogh, which also contain decaying cadmium sulfide pigments. But Monico cautions that every painting is a unique, complex chemical landscape, so conservation strategies must be devised on a case-by-case basis.

Maria Temming is the staff reporter at ScienceNews for physical sciences, covering everything from chemistry to computer science and cosmology. She has bachelor’s degrees in physics and English, and a master’s in science writing.

This article was first published on www.sciencenews.org on May 15, 2020. If you have questions or comments, please send them to feedback@sciencenews.org.

This article originally appeared in the Oct. 9, 2020, issue of The Norwegian American.