An apparatus includes at least one scanner. Each scanner includes a plurality of sensors, and each sensor is capable of measuring one or more characteristics associated with a portion of a substrate. The substrate has printing produced by a printing system. The apparatus also includes a controller capable of receiving at least some of the measurements from the plurality of sensors and determining a quality of the printing on the substrate using the received measurements. The substrate could represent paper, and the printing system could represent an offset printing system. At least one of the sensors may be in a fixed position and/or at least one of the sensors may be movable over part of a surface of the substrate. The determined quality of the printing could involve density, dot area, dot gain, contour sharpness, doubling, mottling, ghosting, misregister of different colored inks, slur, or improper positioning of the printing.