Block of raw leaf gutta percha, 1942-1945.
© Science Museum / Science & Society Picture Library
An inscribed mottled brown rectangular block of gutta percha manufactured in Telcon's (formerly the Gutta Percha Company) plantation in Malaya during the Japanese occupation in World War II. Gutta percha is a close relative of rubber and is obtained as a resin from a tropical tree. It used to be extensively used as an electrical insulator and in the manufacture of golf balls, but has largely been superseded by synthetic materials.