Abstract: A roll-up type industrial door including a flexible vinyl sheet forming a curtain for closing a door way having an upper end, a lower end and two opposite side edges. The sheet has a thin main area and elongate side edge sections that are thicker than the main area. A sloping shoulder is formed where each side edge section meets the main area. A curtain winding mechanism is connected to the upper end of the curtain and is used to raise the curtain. A pair of spaced apart guide channels are also provided and the side edge sections are movable therein. Friction reducing, wear resistant fabric strips are bonded to both of the side edge sections and extend therealong. These strips cover the sloping shoulders and are bonded thereto. The strips reduce the amount of friction between the side edge sections and their respective guide channels. Preferably the strips are made of one ply polyester monofilament.