A method is used to identify a single panel or proof copy that has a printed image of defective quality on printed material that includes several such panels or proof copies. An image of at least part of the printed material is captured photographically. Data, that correlates with the captured image, is analyzed to determine if a defect exists which reduces the quality of the printed image on the printed material. Information with respect to the specific location of the proof copy which contains the defect is determined by comparing the data which correlates with the captured image, to an electronically generated data record which includes information, with respect to the arrangement, form or size of the individual panel that is located on the printed material. An image processing system may perform the comparison of the data record for the form of the individual panel or proof copy on the printed material. That data record may originate from a punching die which is used for separating the individual panels or proof copies of the printed material.