the mystery of the black streaks on his paintings

Pierre Soulages is a prolific French painter. He passed away a few months ago. He particularly liked to work with the reflections of the color black. And something strange has been observed on some of his paintings kept in the reserve of a museum in Toulouse. Peeling paint. Unfortunately, this is fairly standard on aging works. But also, paint that runs. It is much more surprising. So CNRS scientists investigated.

Using luminescence imaging techniques, from ultraviolet to infrared, they concluded that over time, the oil in the paint – the binder for the pigments – could have oozed out. That would explain the drips. Drips also observed, moreover, on other canvases painted in Paris at the end of the 1950s. From a paint coming from a single and unique supplier.

Chemistry at the bedside of art

Another explanation put forward is sulphide pollution. She was present in our capital at that time. Because of the extreme cold of the winter of 1959, in particular, the heaters were running at full speed in the Parisian workshops. This may have altered the composition of the paint applied by the artists to their paintings.

The researchers also consider that the post-processing of the works, their varnishing just after they were made, may have further accentuated the phenomenon. But to confirm either of his hypotheses, scientists will have to conduct some more in-depth chemical analysis. With the hope of finding solutions to protect these works from the attacks of time.