Kroitor exhibited a large-scale multi-screen work, "Labyrinth", at Expo 67 in Montreal. In the same year he co-founded the Multiscreen Corporation, which later became the IMAX Corporation. The Multivision process, which was a response to Kroitor's experiences at Expo 67, was developed for the Osaka Expo '70 and involved 70mm film projected horizontally rather than vertically. Each frame was as large as a postcard, with 15 sprocket-holes.