Abstract: Method for the quality-controlled treatment of surfaces with a radiation-cured surface treatment, in which a finishing formulation is applied to the surface and is polymerically crosslinked under the effect of radiation. To enable the quality control to be conducted non-destructively and at reduced cost, it is proposed that the finishing formulation contains a proton-affinitive indicator substance analyzable by ion mobility spectroscopy and that the indicator substance escaping from the printed or coated surface after the radiation curing is analyzed by means of ion mobility spectroscopy.