German painter and draughtsman. He registered at the Karlsruhe Academy of Fine Arts in 1914 but remained there for only a few months, preferring to work alone.
He lived quietly at Hagnau on Lake Constance, working in isolation, and would not exhibit his pictures under the Nazi regime. The monochrome ink paintings he executed throughout this period were seen by the public only after World War II, making his reputation. From 1950 he took part in many major international exhibitions, including Documenta in Kassel (1959) and the Venice Biennale in 1960. While continuing to work on paper, he also began to paint on panel from 1953 (all destr.) and from 1956 on canvas.