Color quality control can be achieved on lithographic presses through the use of color spectrophotometry. In this system, either the color bar portion of the image or the entire image is scanned. The digital pixels are compared with a reference: either a measuring proof, or some in-house standard. The press can then be adjusted to match the reference. Required adjustments are accurately predicted and measured leading to less waste during the makeready phase. Several presses can also be controlled by the correct color settings, thus eliminating the need to produce waste during the adjustment of each press.

Source: Graphic Arts Monthly, February, 1999, p. 72.