With the rise of color television, the British Broadcasting Company (BBC) began a process of wiping old videotape copies of black and white television programs starting in the late 1960s. The policy was in place due to the high cost of purchasing new videotape for the recording of new episodes, the limited use of old shows with no home video existing at the time, and the (then) current contracts with actor's unions regarding re-airing of television programs. By 1974, all master videotapes were wiped.
