2b - Dye-transfer printing (unedited text)
Technicolor’s superior dye-transfer printing process was its greatest legacy. Introduced for two-color printing in 1926, it was adapted for three-color in the 1930s, and remained in use in the United States until the mid 1970s.
Dye-transfer printing shared many characteristics with lithography, in which an etched metal or stone surface was used to print a dye image or text onto paper. For motion picture use, separate color records had to be imparted onto a blank strip of gelatin-coated 35mm film, 1,000 feet long. Cyan, yellow, and magenta dyes were added one-by-one by pressing a dyed matrix or relief film into contact with the blank for a short time. Exact registration of the dye imprints was crucial.