Subtractive colour processes are methods used in colour printing and photography that rely on the principle of filtering light to remove (subtract) specific wavelengths. In these processes, layers of cyan, magenta, and yellow dyes or pigments are applied over a white light source. Each layer selectively absorbs its complementary colour-cyan absorbs red, magenta absorbs green, and yellow absorbs blue-allowing the desired colours to appear in the final image. By carefully combining these three primary subtractive colours in varying densities, a full spectrum of colours can be reproduced on paper or other media.
This process forms the basis of most colour printing techniques, including traditional photographic prints, inkjet printing, and offset lithography. Subtractive colour systems differ from additive systems, such as those used in screens and projectors, where colours are created by combining light itself. Understanding subtractive colour processes is essential for photographers, printers, and graphic designers, as it affects colour balance, image fidelity, and reproduction quality in printed work, ensuring accurate and visually pleasing results.