bipack means the process of loading two reels of film into a camera, so that they both pass through the camera gate together, formerly used for visual effects and as a subtractive colour process. Lexicurio rates it Sui generis — a strength score of 91 out of 100.
Etymology
From bi- + pack.
noun
- The process of loading two reels of film into a camera, so that they both pass through the camera gate together, formerly used for visual effects and as a subtractive colour process.
verb
- To load two reels of film in this manner.