1. A method to convert color-describing input print data suitable for graphical output with the aid of an output apparatus into color-describing C,M,Y,K output print data, comprising the steps of: determining color proportions, defined by the input print data, of at least one region to be inked with at least two color separations, and determining a color space value to be generated with aid of said color separations; determining an association rule to convert the input print data into the C,M,Y,K output print data while retaining the color space value, wherein a total areal coverage of areal coverages defined by the output print data of the color separations to generate the color space value is reduced for C,M, and Y but not K wherein K total areal coverage therefore remains the same, relative to areal coverages of the color separations defined by the input print data; and converting the input print data into the C,M,Y,K output print data with aid of the determined association rule.