A pile of reference paper conforming to iso 2846-1 is prepared for printing on a sheet-fed press by hand-inserting single, well-marked sheets of other paper types at intervals of approximately 100 sheets. The thickness of the paper types is selected to be roughly equal. The press is supplied with process inks conforming to iso 2846-1. At start-up, the inking levels on the reference paper are controlled such that the CIELAB values of the solid tones of cyan,magenta,yellow, and black conform to iso 2846-1 in the dry state. If necessary, the dry-back effects have to be established before the press run. While printing the remainder of the pile, the inking levels are regularly checked on the reference paper and kept constant there. After drying, the inserted sheets of the other paper types are recovered from the pile; they show the ink colours to be established. If a multicolour test forme was uses for the run, primary and overprint colours are accessed at the same time