Photographic prints combine subtractive colours (cyan, magenta and yellow) to create all colours.
All of the subtractive processes share a dependence on the light sensitivity of silver halides, the primary difference between processes lies in how the dyes are formed and deposited. The order of the CMY layers varies between processes.
The four image-making processes considered in this study are the dye coupler process, the dye destruction process, the dye diffusion transfer process and the internal dye diffusion transfer process.