Van Gogh’s sunflowers are wilting as paint fades

Brussels: The Van Gogh Museum in Amsterdam is reviewing how it displays the artist’s Sunflowers painting after a pioneering new technique revealed the painting’s petals and stems were withering to an olive-brown colour as a result of his use of a light-sensitive yellow paint.

A laborious x-ray scan of the painting’s canvas has discovered that Vincent van Gogh used two different types of a chrome yellow paint, one of which is more liable to degrade under light.

The change in the 1889 painting, one of a series of sunflowers by Van Gogh, is so far not visible to the human eye but, over time, the painting is set to lose some of its vibrancy in the pale-yellow background and the sunflowers’ bright yellow petals and stems, where the sensitive pigment was mixed to achieve the right green hue.

The orange parts of the background to the flowers is unlikely to degrade in any significant way as Van Gogh used a less sensitive yellow paint, with a lower content of sulphur.

“It is very difficult to say how long it would take for the change to be obvious and it would depend a lot on the external factors,” said Frederik Vanmeert, a materials science expert at the University of Antwerp, who was part of the team examining the painting in research commissioned by the museum.

“We were able to see where Van Gogh used the more light-sensitive chrome yellow, the areas that the restorers should look out for over time for discolouration … We were also able to see that he used emerald green and a red lead paint in very small areas of the painting which will become more white, more light, over time.”

The discovery follows two years of analysis by a team of Dutch and Belgian scientists.