Smell-O-Vision is a system that released odor during the projection of a film so that the viewer could "smell" what was happening in the movie. Created by Hans Laube, the technique made its only appearance in the 1960 film Scent of Mystery, produced by Mike Todd Jr., son of film producer Mike Todd. The process injected 30 odors into a movie theater's seats when triggered by the film's soundtrack.
Roughly similar concepts integrating odor experiences into entertainment performances date back at least to 1868 for live theatre, with the first film usage in 1906. Other approaches include General Electric's "Smell-O-Rama" in 1953 and the rival "AromaRama" system in 1959. In cheeky homage to this era, John Waters enhanced his 1981 film Polyester with an "Odorama" scratch-n-sniff card.