The process of photographically slicing a colour image into two or more (usually 3) colour components. Each colour is separated by printing the image through a narrow pass filter, which transmits a very narrow range of wavelengths and absorbs all others. The filters used for this process are chosen so that the full gamut of colour is represented when the three separations are recombined.


Separation masters are three separate black-and-white master positives made from one colour negative; one containing the red record, another the green record, and the third the blue record.