Abstract: A master chart comprises a representation of various blocks (1) of color produced by suitable combinations of the base colors cyan, magenta, yellow and black (C,M,Y,K) . There are also illustrations of color prints (2) which are to be printed by a copying machine onto a sheet. For the color standardization procedure test sheets are provided onto which the images from the master chart are to be printed. These carry the same array of color blocks (1A) and picture representations (2A) but the block and color representations are offset with respect to the positioning of the corresponding blocks on the master chart. The operator compares the various color blocks against one another and make an estimation as to what adjustments are needed to the copier to ensure that a more acceptable print is achieved.