Sunflowers by Vincent van Gogh and X-ray. Photo: National Gallery, London
The X-ray picture of the famous painting by Vincent van Gogh “Sunflowers” from the museum of the artist in Amsterdam showed that the sensitive paint used by him for the image of petals and stems is gradually losing saturation. In a two-year study commissioned by the museum, it turned out that Van Gogh used two different types of yellow pigment. One of them is prone to greater degradation due to the chromium contained in it, which darkens when exposed to light. While color changes are almost invisible to the naked eye, and to predict how the shades will change in the future, it is difficult, because, according to the expert from the University of Antwerp Frederic Vanmert, it depends on many factors. Separate fragments of Van Gogh painting can, over time, brighten. “In small areas, the artist used emerald green and red paint with lead, these plots may become lighter in the future.” Experts on the color changes in the paintings of the Impressionists and Post-Impressionists experts from Belgium and France reported three years ago, linking this with the use of yellow cadmium in colors. To minimize damage, they urged the museums that own the paintings of these artists to reduce the illumination in the halls, which several years ago was done at the Van Gogh Museum.