A method for checking and correcting the position of a blank comprised of three flaps arranged in a row, the method including the following steps: closing the right- and left-hand flaps one above the other at least in an overlapping portion, gluing the flaps together; positional checking of the right-hand edge and the left-hand edge and comparing those edges with a predetermined position in order to determine a positional deviation of the flaps and, if the positional deviation exceeds an admissible deviation value, then before the glue sets, fixing the central flap at a location via the lower face of central flap using a fixing device using vacuum-induced negative pressing, then holding the upper face of the right-hand flap and of the left-hand flap by respectively at least one suction cup which applies vacuum, and correcting the position of the left-hand flap and/or of the right-hand flap by moving the suction cups sideways.