Non conductive supports flank the mounting location of ribs for a wire wrap screen so as to limit penetration into the wire being fed over the ribs and resistance welded notwithstanding variations of applied force from the weld roller. Optionally the wire can be pre-rolled to approximately its end diameter in the finished screen ahead of the time it contacts a rib so as to minimize bending the wire over the rib which thins the wire. The supports are preferably ceramic and provide equal penetration of the rib into the wrap wire despite variations in loading by the weld roller.