Definitions for "RICH BLACK"
Keywords:  cyan, magenta, deeper, darker, yellow
A black color that is made by mixing other colors of ink with black ink. This produces a much darker, deeper black on press than can be achieved by using black ink alone. Typical values for rich blacks are 40% Cyan, 100% Black or 40% Cyan, 30% Magenta, 30% Yellow, 100% Black.
A darker and deeper black color achieved by combining other ink colors with black ink. The values to create Rich Black is usually 40% Cyan, 30% Magenta, 30% Yellow, 100% Black
Because of impurities in commercial printing inks 100% solid black generally appears nearer to a dark grey. Because of this, printers often add a 'wash' of other coloured inks to create a rich black. Typically this is 40% of cyan, but other combinations of cyan, yellow, magenta and black are not unknown.