Edvard Munch’s “The Scream”, which unfortunately encapsulates our times quite nicely, has resided at the Munch Museum in Oslo for many years. But since 2006, the museum has kept the painting in storage, concerned about the degradation of its pigments. The major problem is that much of the yellow paint in the sky, in the water, and around the angst-ridden figure’s face is fading, cracking, and flaking away. Much of it already appears nearly white.
There are actually two painted versions of “The Scream": the Munch Museum’s specimen, from about 1910 (pictured above), and the one at the National Museum (also in Oslo), painted in 1893. The earlier version was rendered in tempera and crayon and does not seem to be degrading all that much:
For the 1910 version, however, Edvard Munch took advantage of newfangled-at-the-time cadmium yellow pigment (primarily cadmium sulfide), which is very brilliant but was often manufactured back then in a way that left it unstable. Until now, the reason for this instability had not been clearly understood. Is it light? Heat? Moisture? Dryness? How can we stop it? So the Munch Museum has kept “The Scream” in the dark and out of public view.
The fading of the yellow color is already quite significant, as shown by this digital reconstruction of what part of the sky once looked like:
Fortunately, a study published Friday in Science Advances, led by Letizia Monico and Costanza Miliani of the University of Perugia (Italy), has shown that the primary reason for the fading and cracking is not light but moisture, and that therefore the painting can safely be displayed under normal lighting and 45% humidity or less. You can’t display a painting without light, of course, but humidity is something that can be managed.
So “The Scream” can be exhibited once again!
This hopeful result will also apply to a significant percentage of other paintings rendered in the late 1800s and early 1900s, such as some by van Gogh and Matisse, which are losing their yellows in a similar way that up to now has not been understood.
The bright yellow pigment cadmium sulfide occurs in nature, but only rarely. Its natural forms are the minerals greenockite and hawleyite. They often occur as coatings on ores of metals similar to cadmium, like zinc:
Even in 1888, cadmium sulfide, or “cadmium yellow”, was called “a perfect color if not so expensive." (And not so toxic, but nobody knew that at the time.) It began to be manufactured synthetically at a reasonable scale around then, so it became accessible enough that artists like Munch, van Gogh, Matisse, and Monet could begin to use it, and they eagerly did so because of its brilliance. Perhaps the best look at how the yellow would have appeared originally:
These kinds of synthetic pigments were all the rage among Impressionists and Expressionists, but van Gogh even at that time was aware that they would fade:
“I’ve just checked — all the colours that Impressionism has made fashionable are unstable,” van Gogh wrote to his brother Theo, in 1888, “all the more reason boldly to use them too raw, time will only soften them too much.”
The alteration over time of many of van Gogh’s colors is well-known now, coming to light especially in the last ten years or so. For example, van Gogh’s “The Bedroom” (1889):
And a digital reconstruction of its original appearance:
One reason the Munch Museum has been so concerned about light exposure in particular is that the yellows and greens in van Gogh’s “Sunflowers”, for example, which are based on chromium salts, are known to be turning brown due to photo-oxidation (reaction with oxygen upon exposure to light). That’s a bit of a problem for displaying it under lights in a museum.
But Monico and Miliani have shown that the main problem for the cadmium sulfide yellow in “The Scream” is not light exposure … but moisture. They showed that cadmium sulfide (even from Munch’s original paint tubes, which they had access to) is most vulnerable to oxidation in the presence of moisture, whether in light or in dark. It turns into cadmium sulfate, which looks like this:
Seems pretty simple, right? Cadmium sulfide (CdS) takes on oxygen to become cadmium sulfate (CdSO4). But it’s not simple at all, and sometimes extensive study is required to find out how it actually happens in a particular context.
Monico and Miliani (and a bunch of others involved in Friday’s study) used sophisticated spectroscopy and accelerated aging techniques to figure out that the white color was cadmium sulfate in the first place, that it wasn’t present originally, and then how exactly it was forming.
They also tracked the impurities (chloride and carbonate) present in the cadmium yellow, revealing the rather sloppy process by which it was manufactured. These impurities could even be culprits in accelerating the fading and flaking process. This context will help identify other paintings that should benefit from the same treatment.
A lot of work, but the effort has been worth it!
If you happen to be in Norway, by all means work together to get rid of coronavirus first, but then get over to the Munch Museum and see a piece of your country’s history! It’s coming back!
The Norwegians know, by the way, the exact spot that Munch depicts in “The Scream”. There’s a fun writeup about this by Bob Egan here. If you’re walking on Ekeberg Hill in Oslo on a road called Vallhallveien, you’ll run into this plaque:
The plaque in context:
Keep on walking up the road a little, and you’ll be standing at the spot Munch was when he “felt as though a scream went through nature”:
Oslo looks a little happier these days.