Wallace Carothers, the director of research at the American DuPont Corporation, invented nylon in 1935. He had previously studied chemistry, and specialised in polymers. They are molecules composed of long chains of atoms. Nylon was a strong but fine synthetic fibre which was first mass produced in 1939. It was/ is used to make a wide range of products which included/ include stockings, toothbrushes, parachutes, fishing lines, and surgical thread.