German painter who, between 1964 and 1971, studied at the Düsseldorf Art Academy under Joseph Beuys. Early in his career, he had frequent contact with Imi Giese and Palermo and worked mostly with light projection. In 1968, he had his first one-man show in Copenhagen and made his first space installations with fibre plaques. Between 1969 and 1975, he experimented with a single line in several paintings and, in 1972, he produced video X for Gerry Schum's video gallery. Between 1972 and 1987, he participated in documenta 5, 6, 7 and 8 in Kassel. The period between 1976 and 1981 is marked by the production of Mennige Pictures with construction designs cut out of white paper. Early in the eighties he created large size environments with rectangular lengths cut out of coloured paper and later placed in layers piled up and hung. Influenced by Suprematism and Russian Constructivism, Knoebel's abstract geometry centres on the fundamental problems of painting and form.