Within the CMY color space, any hue angle can be achieved by combining two of the three primaries. The intention of the third color is to move that hue towards grey (decrease saturation), and is known as the greying agent. However, as that greying agent has an inherent hue of its own, it also shifts the hue as it changes the saturation of the resulting color. The most efficient way to change the saturation of a given color while maintaining the same hue angle is to use the Key (Black) component. The act of substituting a quantity of black for a quantity of the greying agent is known as "Grey component replacement."
In grey component replacement (GCR), contrary to under color removal, the CMY values that add to grey all along the tone scale can be replaced with black ink. Grey component replacement only adds black to the CMY equivalent of what would have printed as a grey.
- Advantage: Black ink can be less costly than colored inks.
- Advantage: The resulting output is less susceptible to changes in the printing variables since you are not continually trying to balance as much C, M, and Y.
- Disadvantage: As a result of impurities in the C, M and Y primaries, some colors can appear dirty or may shift.
Famous quotes containing the words grey, component and/or replacement:
“That reverend Vice, that grey Iniquity, that father Ruffian,
that Vanity in years.”
—William Shakespeare (1564–1616)
“... no one knows anything about a strike until he has seen it break down into its component parts of human beings.”
—Mary Heaton Vorse (1874–1966)
“Not even the visionary or mystical experience ever lasts very long. It is for art to capture that experience, to offer it to, in the case of literature, its readers; to be, for a secular, materialist culture, some sort of replacement for what the love of god offers in the world of faith.”
—Salman Rushdie (b. 1947)