... main backings are: Paper, Cloth, PolyesterThe main abrasive coatings: Aluminum Oxide, Silicon Carbide, Zirconia, GarnetJoint: Lap joint/butt ... main backings are: Paper, Cloth, PolyesterThe main abrasive coatings: Aluminum Oxide, Silicon Carbide, Zirconia, GarnetIt consists of emery ... Narrow belts are made of our flexible-backed aluminum oxide sandcloth. The added flexibility allows for optimum sanding ...