Rich black, in printing, is an ink mixture of solid black over one or more of the other CMYK colors, resulting in a darker tone than black ink alone generates in a printing process. A typical rich black mixture might be 100% black, 50% of each of the other three inks. Other percentages are used to achieve specific results, for example 100% black with 70% cyan (C), 35% magenta (M), and 40% yellow (Y) is used to achieve "cool" black. "Warm Black" is 35%C, 60%M, 60%Y, and 100%K. The colored ink under the black ink makes a "richer" result; the additional inks absorb more light, resulting in a closer approximation of true black. While, in theory, an even richer black can be made by using 100% of each of the four inks, in practice, the amount of non-black ink added is limited by the wetness that