1. An inspection system for inspecting deposits printed on workpieces through a printing screen, the system comprising: a camera unit movable relative to a printing screen, where comprising a body including a plurality of apertures, and a workpiece on which deposits are printed through the apertures of the printing screen; wherein the camera unit captures images of at least one pair of corresponding regions of a lower surface of the printing screen and an upper surface of the workpiece; and a processor configured to process the images to determine, in turn, for each of a plurality of points defining the image of the printing screen, the image of the printing screen comprising both the body of the printing screen and apertures within the printing screen, whether the point is of aperture, and, only where the point is determined to be of aperture, determine whether the corresponding point of the corresponding image of the workpiece, as defined by a corresponding plurality of points, is of deposit, thereby enabling a determination of a print characteristic of deposits printed on the workpiece from a relationship of the points determined to be of deposit to the points determined to be of aperture.