A method of inspecting the quality of blanks (2n) to be processed into packaging material, includes the following steps: A carrier (1) with a plurality of blanks (2n) is supplied. Each blank (2n) is identified in accordance with its position (n) on the carrier (1), and a scanned image (Sn) of each blank (2) is obtained, and each scanned image (Sn) is compared with a reference image (Rn) associated with the specific position (n) of the blank (2n) from which the image was taken. Based on the result of the comparison, the respective blank (2n) is accepted or rejected. Furthermore, there is a quality inspection system (10) comprising a digital imaging unit (12) for scanning images of blanks (2n) on a sheet (1), a unit (16) for generating individual reference images for each blank, a storage (18) for storing the individual reference images (Rn), and a comparator (20) for comparing scanned images (Sn) of a blank with the individual reference image (Rn) for this blank (2n).