Technicolor Process 1 (Additive System) - The Gulf Between (1917): A prism beam-splitter behind the camera lens exposed two consecutive frames of a single strip of black-and-white negative film simultaneously, one behind a red filter, the other behind a green filter.
Process 2 (Subtractive System) - Toll of the Sea (1922), The Phantom of the Opera (1925), The Black Pirate (1926): The frames exposed behind the green filter were printed on one strip of black-and-white film, and the frames exposed behind the red filter were printed on another strip. After development, each strip was toned to a color complementary to that of the filter—red for the green-filtered images, green for the red-filtered.
Process 3 - Mystery of the Wax Museum (1933): Every other frame of the camera negative was printed onto one strip of specially prepared gelatin film (or “matrix”) to create a red record, and the remaining frames were printed onto a second strip of blank film to create a green record.
Process 4 - The light passing through the camera lens was split into two beam paths by a prism block. Green light was recorded through a green filter on panchromatic film, while the other half of the light passed through a magenta filter and was recorded on bipack film stock with two strips running base to base. On this stock, the front film was sensitized to blue light only, backed by a red gelatin layer which acted as a light filter to the panchromatic film behind it.
