APP QUARTZ sanding discs are high-quality coated abrasives based on a synthetic film which provide a perfect surface finish with uniform scratch pattern. Thanks to their sturdy increased-density abrasive grit with open coating made of fine white aluminium oxide, the APP QUARTZ sanding discs may be used to grind the following surface types: a) easy-to-treatment surfaces such as polyester products, e.g. Universal putty APP Compact / Supra, b) medium-hard dusting surfaces, e.g. Acrylic primers, c) high-resistance surfaces, e.g. Universal putty APP Poly Plast, while providing excellent surface finish.