Non-PSA Sanding Discs (discs without Pressure Sensitive Adhesive) work similarly to PSA sanding discs but require an adhesive to be applied to the backing of the disc. Similar to PSA sanding discs, Non-PSA Sanding Discs are designed for lighter duty blending, medium stock removal, finishing, and polishing. Discs can have a cloth, film, or paper backing. Non-PSA sanding discs may be solid or have vacuum holes for dust removal. The common abrasive materials include aluminum oxide, alumina zirconia, silicon carbide, ceramic, and diamond. Choose from very coarse to ultrafine grade, or corresponding grit, depending on material being worked and level of precision required. Some paper- and film-backed discs are available as a continuous disc roll.