Born 1924 in Okucani, Croatia. Painter, printmaker, sculptor and designer. Studied at the Zagreb Academy from 1943 to 1946. 1951-1956 co-founded of the Exat 51 group, together with fellow architects and painters. 1956 co-founded Industrial Design Studio (SIO). He showed his fascination with design and plastic thinking in 1948 while designing exhibition premises in Zagreb. Picelj was involved in the origins of the international movement, New Tendencies, 1961-1967, which promoted Zagreb as a centre of new European Constructivism and Op art. Worked a great deal with the Denise Rene Gallery, Paris. Picelj organized the first exhibition of industrial design in Zagreb in 1955. He did reliefs in wood and metal from 1957, structured of equal or close elements. He had his first one-man show in 1952 and since then he participate on numerous solo and group exhibitions all over the world. For his works he was awarded on several occasions in Croatia and abroad. Lives in Zagreb.