Sandpaper

Sandpaper consists of a flexible paper backing, with a film of adhesive (glue) that holds and supports a coating of abrasive grains. Sandpaper belongs to a class of materials called "coated abrasives." The first record of a coated abrasive is in thirteenth-century China, when crushed seashells were bound with natural gums to backing material. The first known article on coated abrasives was published in 1808. It described how heat-processed, ground pumice (a type of abrasive) was mixed with varnish and spread on paper with a brush.

Most abrasive papers are now made with aluminum oxide or silicon carbide, although they are still called "sandpaper." Quartz grains are also used for wood polishing. The paper used is heavy, tough, and flexible. The grains are bonded with a strong glue made from a variety of resins.