Sandpaper is a common abrasive medium consisting of particles bonded to a flexible backing. Although the name evokes ordinary sand, modern sandpapers use manufactured abrasives such as aluminum oxide, silicon carbide, garnet and ceramic grains. Backings range from simple paper to cloth, polyester film or vulcanized fiber. The choice of abrasive, bond and backing determines durability, flexibility and suitability for hand or machine sanding.
Composition and types
Typical sandpaper is described by three elements: the abrasive grain, the backing material and the adhesive or bond. Coated abrasives have grains applied to one side of the backing; bonded abrasives (for example, grinding wheels) use a matrix that holds the grains together. Common varieties include:
- Coated paper or cloth sheets and discs for general woodworking and finishing.
- Belt and drum abrasives for heavy stock removal or sanding large surfaces.
- Wet/dry papers that tolerate lubrication to reduce dust and achieve finer finishes.
- Emery and sandcloths for metal and specialty uses.
Grit and grading
Sandpaper is graded by grit size: lower numbers mean larger, more aggressive particles; higher numbers indicate finer abrasives for polishing. Common ranges are coarse (rough shaping), medium (smoothing), fine (preparing for finish) and very fine or superfine (polishing). Different grading systems exist; manufacturers and regions may label grits differently, so compare intended use rather than only the number.
History and development
People have used abrasive materials for surface finishing for millennia, applying crushed stone, shells or sand to cloth or paper-like backings. The industrial era brought manufactured mineral abrasives and standardized production of coated papers and cloths, enabling a wide variety of grits and bonds and the development of powered sanding tools. Over time, synthetic abrasives largely replaced natural sand because they cut more predictably and last longer.
Uses, techniques and safety
Sandpaper is essential in woodworking, metalworking, automotive refinishing and DIY projects. Typical tasks include removing old finishes, blending joints, shaping edges and creating a surface ready for paint or varnish. Hand sanding allows fine control; powered sanders such as random-orbit or belt sanders increase speed but require skill to avoid gouging. For guidance on selection and methods see the manufacturer's specifications and technique references like sanding guides.
Safety considerations include using dust extraction or wet sanding where appropriate, wearing eye protection and respiratory filtration, and matching abrasive aggressiveness to the material to prevent damage. Proper progression through grits and consistent pressure produce the best results while extending the life of the abrasive.
Notable distinctions: "sandpaper" is a general term; when fabric backings are used and flexibility is required, terms like "sandcloth" or "emery cloth" may apply. Pressure-sensitive adhesive (PSA) versions simplify disc attachment to machines. Understanding backing, bond and grit together helps select the right abrasive for a given task.