This is a disturbing phenomenon that intrigues scientists. On some canvases by Pierre Soulages, master of the Outrenoir, drops of paint have appeared. At the University of Cergy, a restorer and Soulages specialist is worried. “Normally a painting, when it ages, it cracks and becomes more and more brittle. And there, it is the completely opposite phenomenon which takes place ”, wonders Pauline Hélou de la Grandière with France Info.
"It's really sticky. If we look under the UV lamp, we see a little hiss. We see something a little brighter and small drops forming. And when they are really formed, it can be a flow several centimeters long that comes out of a wheelbase,” observes the researcher.
The canvases concerned all date from the same period: they were painted in Paris between “December 1959 and March 1960”. An important common point according to the specialist. For the moment, no certainty can be advanced, but according to Pauline Hélou de la Grandière, the paint supplier could be blamed, just like “the heavy sulphide pollution” in Paris.
A team, made up of researchers from the CNRS and the Saint-Étienne Optical Institute, led by the researcher, is mobilized to find the solution to this mystery. Each avenue is explored: "these are also paintings that were exhibited immediately after their creation, in exhibitions that sometimes went very far, so that were immediately stored in boxes, put in the dark and with variations in climate”.
A total of ten works would be affected. “What is very strange is that paintings by other artists who created works in Paris, in the same periods, are concerned,” explains Pauline Hélou de la Grandière.
Scientists are also trying to find a solution to limit the phenomenon or even prevent it. For the moment, no lead is conclusive. "Each time we find a hypothesis, it must be verified in the works that have the same problem and especially that it not be verified in the works that have no problem", explains the researcher .
Two tracks are preferred: the paint supplier and the drying conditions. Pauline Hélou de la Grandière noted that "this is not a problem found among Americans contemporary with Soulages, for example, except when they came to work in Paris".