120 is a film format for still photography introduced by Kodak for their Brownie No. 2 in 1901. It was originally intended for amateur photography but was later superseded in this role by 135 film. It survives to this day as the only remaining medium format, popular with professionals and amateur enthusiasts.
The 120 format is typical of roll film. The spool was originally made of wood with metal flanges, later all metal, and finally plastic. Frame number markings for the three standard image formats are printed on the backing paper. The film is 72 cm long.
