23. A Montparnasse Disease? Severe Manifestations of Metal Soaps in Paintings by Pierre Soulages from Around 1959 to 1960 (Delaminating Oil Paint Layers, Medium Exudates, Discolorations)

Pierre Soulages (b.1919) is the most renowned French painter alive today, well-known for his use of the color black. During his long and prolific career (around 1500 paintings made to date), he has worked with various oil paint techniques and later on acrylics, making continuous use of the color black. This paper deals with paintings from the end of the 1950s, where black paint was layered on and then scraped off with tools to reveal colored underpainting (Fig. 23.1). The creation process of Pierre Soulages has often compelled him to adapt his tools (Ragon 1990; McEnroe 1991; Encrevé 1995) and to innovate in his use of materials. Yet he has always remained interested in understanding the physical phenomena of the drying process, discussing the subject with friends such as Marc Havel, chief engineer at Bourgeois and connoisseur of painting techniques (Havel 1974), or Pierre-Gilles de Gennes, winner of the Nobel Prize in Physics. Paradoxically, in spite of this constant interest, some of his paintings from an important period in the 1950s–1960s are deteriorating. This paper focuses on those paintings, their specific patterns of degradation, and the roles that technique and material composition have played in the process.