1. A method of determining colorant amounts to be laid down in a color printer comprising: inputting an initial set of cyan, magenta and yellow (CMY) input values; defining a gamut center black generation curve; defining a gamut boundary black generation curve; extending a surface between the gamut center black generation curve and the gamut boundary black generation curve; calculating a final set of CMY values; interpolating a black colorant amount for the final set of CMY values on the surface.