A device is provided for use in storing a blanket that is to be exchanged on a cylinder of a printing machine and which has a plurality of blankets on its periphery. The blanket to be exchanged is stored in a tray that includes at least one code reader which will detect a characteristic that was applied to the blanket for purposes of its identification. The detected characteristic is matched with a plan that is used to accomplish a planned printing process. If a discrepancy in the match is noted, a message, which warns of the presence of an incorrect blanket, is generated before that incorrect blanket is mounted on the cylinder.