A method of making wallboard including the steps of providing an unfinished length of wallboard that has a recess along its longitudinal edges by conveying it upon a conveyor in a first direction in a step, forming recesses in the unfinished length of wallboard at both lateral edges thereof, selecting an apparatus for forming the recess from a plurality of device for forming the recess, forming the recess with the selected apparatus, and separating the unfinished length of wallboard at a location of the recess to form finished lengths of wallboard, such that the finished lengths of wallboard have recessed lateral edges. Also disclosed is a system for performing the method.