Whiteboard
Whiteboards became commercially available in the early 1960s, but did not become widely used until 30 years later. Early whiteboards needed to be wiped with a damp cloth and markers had a tendency to leave marks behind, even after erasing the board. Dry-erase markers for whiteboards were invented in 1975.
Clapperboard
The clapper (two sticks hinged together) was invented by F. W. Thring (father of actor Frank Thring), who was head of Efftee Studios in Melbourne, Australia. Some mention that Efftee was not founded until 1931, not in the 1920s as sometimes stated. However, the date of Efftee's founding does not assume the start of F.W. Thring's involvement in the industry. Consider the start of the Australian film industry with 1906's The Story of the Kelly Gang, which was the first feature length narrative film in the world. The director of this film, Charles Tait, was associated with J. C. Williamson. The former's production company, J. & N. Tait, merged with the J. C. Williamson Film Company. F.W. Thring was managing director of J.C. Williamson Films in 1918. The clapboard with both the sticks and slate together was refined by Leon M. Leon (1903–1998) a pioneer sound engineer.