Abstract: To provide a reinforced paper sheet which has curl-resistant edges so that it will not jam high-speed copier machines, the edges of the paper sheets are reinforced with very thin Mylar strips which are symmetrically mounted on both sides of the edge of the sheet of paper. The strips are preferably about one-half inch wide and may be mounted slightly back from the edge of the sheet of paper. In the manufacturing step, it is desirable that the two strips be applied precisely symmetrically, and preferably simultaneously, so that any stresses are equal and opposite on the two sides of the paper so that the paper resist curling. The Mylar strips may be very thin, such as one-half of a thousandth of an inch in thickness, and the adhesive may be a hot melt type of adhesive which is strictly confined to one side of the Mylar reinforcing strips.