While the exhibition dedicated to Vincent Van Gogh at the Vittoriano in Rome is about to close after being extended for another two weeks by popular demand, a research carried out by the Italian CNR, the University of Perugia’s Department of Chemistry, the University of Antwerp’s Departments of Chemistry and Physics, the Delft University of Technology (TUDelft) and by the Esrf (European Synchrotron Radiation Facility) in Grenoble has discovered why the yellow color of the sunflowers painted by the great painter is turning brown.

In essence, the lead chromate used to create the yellow color that originally was so intense has a low photochemical stability and in time the contact with ultraviolet rays and substances in the environment causes the formation of chromium oxide and some other compounds in a thin layer that becomes brown.

Van Gogh, like many other painters of the period, used various types of colors that were the result of the developments in the chemistry of the XIX century, but the long-term effects of exposure to light and weather showed how some of them have begun to deteriorate unlike the traditional colors that resist better over the centuries.

The researchers took microsamples from the paintings “Bank of the Seine” and “View of Arles with Irises” kept in the Van Gogh Museum in Amsterdam and have used them to compare the deterioration with that of other color samples from leftover tubes aged them artificially to study their reactions by subjecting them to different types of spectrometric analysis.

The problem was shown in the Van Gogh’s paintings where that color was used a lot but it also concern paintings by Manet, Renoir, Pissarro and Suerat.

[ad name=”Google Adsense 300″]

Now that the nature of the changes in the yellow color has been understood the next phase of research will determine exactly what conditions cause it, also considering that the paintings at the National Gallery in London haven’t suffered such damage.

Discovering the cause of the alteration is critical because otherwise the only safe solution is to avoid exposing them to the public and that would be really sad. It’s possible that an appropriate adjustment of the lights and an air conditioning system of the premises where the paintings are exposed is enough to preserve them. Let’s hope so because the solution would be relatively simple: it’s obviously fundamental to save these paintings from degradation but it’s also important that people can keep on admiring them!