These are our "STEARATE" sheets. They are Aluminum Oxide, resin bonded, paper-backed for long life and tear-resistance. This material is recommended for bare wood sanding and autobody use. Applications include sanding of bare metal, primer surfacer and between coats of paint, lacquer and shellac. Also useful on sanding of solid surface countertops such as CORIAN, FOUNTAINHEAD and AVONITE. Our very high quality Zinc Stearate material, added in the size coat, will outperform virtually all competitors.