Painter, born in Biłgoraj, Poland, who settled in England after World War II. Imprisonment in a Siberian labour camp in 1939 and service as a Royal Air Force Spitfire pilot, 1942–5, had a lasting effect on his artistic development. Studied at Central School of Arts and Crafts, Slade School of Fine Art, 1947–50, after initial education in Poland. Had first solo show at London Gallery in 1947, then exhibited widely, including France, Germany, America and Brazil. He was given a retrospective at Warsaw Gallery of Zachęta in 1974; in 1999 shows at the Polish Cultural Institute and Whitford Fine Art traced Knapp’s course through a type of Surrealism, freeform abstraction and Pop Art influences. Although he established a reputation for subtle spraygun pictures, Knapp was also noted for his painting in glass on steel and for his paintings on enamel, fired in a kiln developed by him.