If you look at the real stripper screen its obvious. Hold it level and look at the holes. In one direction you can see thru it. Rotate it the other direction and you can't. The holes are punched at an angle. It's also a good idea to wrap it around a pice of tig rod on the ends for stiffness. It's not super strong. also make sure the washers fastening it are smooth with no sharp edges. It can crack.
Doug