After military service in World War I he became active in the Cologne Dada scene, publishing in 1920 the "Krüppelmappe" ("Cripples Portfolio").
He became active in the Cologne Dada scene. This was after military service in World War I. He was publishing in 1920 the "Krüppelmappe" ("Cripples Portfolio"). This was after military service in World War I.