After moving to Paris in 1946, Pierre Soulages began using walnut stain to make gestural abstract paintings on paper and, by the 1950s, had begun using oil on canvas. Along with Hans Hartung, Georges Mathieu, Serge Poliakoff, and Jean-Paul Riopelle, Soulages is considered one of the major figures of post-war European abstraction, although he resisted attempts to link him with Art Informel or its American relative Abstract Expressionism, in particular claims that he drew inspiration from Franz Kline. One of Soulages main preoccupations has been with the interaction of light and reflection on black paint. In the “Outre Noir” (Beyond Black) series, he alternates areas of matte and gloss black paint, interrupting the smooth surfaces with ridges, scores, and gashes.