A screen printing apparatus and method for printing deposits of a print medium on workpieces, the apparatus comprising: a frame support unit for supporting a printing screen unit which comprises a screen sheet which includes at least first and second patterns of print apertures; a workpiece support unit; a print head unit; and at least one screen cleaning unit; wherein the at least one screen cleaning unit and the print head unit are operated in parallel, whereby, when the printing screen unit is in the first printing position, the at least one screen cleaning unit cleans the underside of the screen sheet at a location corresponding to one of the first and second sets of print apertures and the print head unit prints print medium onto workpieces through the other of the first and second sets of print apertures.