A method of operating a printing apparatus, the apparatus having a rotatable imaging member and an imaging station useful in creating printable images and test patches on the rotatable imaging member. Data is obtained relating to images desired to be printed in a time-frame corresponding to a predetermined number of rotations of the imaging member. A gap is identified in the time-frame corresponding to a location on the imaging member that is not occupied by an image desired to be printed within the time-frame. The identified gap is identified as suitable for receiving a test patch.