METHOD FOR CONTROLLING THE CURING DEGREE OF AT LEAST ONE AT LEAST PARTIALLY CURED INK AND/OR VARNISH PRINTED ON A SUBSTRATE

The present invention relates to a method for controlling the curing degree of an at least partially cured ink and/or varnish printed on a substrate, which comprises the following steps:a) providing a substrate, which is printed with the at least partially cured ink and/or at least partially cured varnish, wherein the at least partially cured ink and/or at least partially cured varnish comprises at least one extractable compound,b) cutting at least one sample from an area of the printed substrate provided in step a), placing the at least one sample in a solvent, in which at least one of the at least one extractable compound is soluble, incubating the solvent with the at least one sample placed therein for at least 10 seconds and removing the at least one sample from the solvent to obtain a solvent extract,c) quantitatively measuring a spectroscopic characteristic of the solvent extract at at least one wavelength between 190 and 4,000 nm, at which at least one of the at least one extractable compound absorbs or emits radiation, so as to obtain a measured numeric value of the spectroscopic characteristic,d) comparing the measured numeric value of the spectroscopic characteristic measured in step c) with a reference value of the spectroscopic characteristic for the same area of the printed substrate, from which the at least one sample has been cut out in step b), ande) outputting a result,wherein the reference value of the spectroscopic characteristic for the same area of the printed substrate, from which the at least one sample has been cut out in step b), has been obtained by the use of an empirical model.