Abstract: A screen printer has a flat bed coplanar with a loading and an unloading surface on opposite sides thereof, the bed being divided into a stationary middle section and two movable outer sections confronting one another along boundary lines paralleling the direction of movement of copy sheets from the loading surface to the unloading surface. Such movement is effected with the aid of a conveyor comprising two chains underneath the bed entraining sheet-gripping jaws through the gaps formed between these sections when they are transversely separated. The jaws are almost flush with the plane of the bed and the loading and unloading surfaces; upon closure of the bed sections, they are received in cutouts of the outer sections and are thus immobilized while a printing screen descends into contact with a copy sheet overlying the bed.