Sun gold Abrasives 9-Inch x11-Inch Sanding Sheets Non-Loading Stearate Heat Treated Aluminum Oxide on a C-Weight backing. Grain is bonded with a full resin over resin bond which is the strongest bond and is also waterproof. Sun gold Abrasives have been manufacturing coated abrasive products for over 37 years. Can be used for sanding of wood, metal, composites, finishes, paint..