Sandpaper

[1] In the modern manufacture of these products, sand and glass have been replaced by other abrasives such as aluminium oxide or silicon carbide.

Sandpaper is produced in a range of grit sizes and is used to remove material from surfaces, whether to make them smoother (for example, in painting and wood finishing), to remove a layer of material (such as old paint), or sometimes to make the surface rougher (for example, as a preparation for gluing).

The first recorded instance of sandpaper was in 13th-century China when crushed shells, seeds, and sand were bonded to parchment using natural gum.

[4] Boiled and dried, the rough horsetail plant is used in Japan as a traditional polishing material, finer than sandpaper.

Glass paper was manufactured in London in 1833 by John Oakey, whose company had developed new adhesive techniques and processes, enabling mass production.

Glass frit has sharp-edged particles and cuts well whereas sand grains are smoothed down and do not work well as an abrasive.

Cheap sandpaper was often passed off as glass paper; Stalker and Parker cautioned against it in A Treatise of Japaning and Varnishing published in 1688.

[5] In 1921, 3M invented a sandpaper with silicon carbide grit and a waterproof adhesive and backing, known as Wet and dry.

[6] In addition to paper, backing for sandpaper includes cloth (cotton, polyester, rayon), PET film, "fibre", and rubber.

Common substrates are paper, cloth, vulcanized fiber, and plastic films and come in grit sizes range from very coarse (≈2 mm) to ultrafine (submicrometre).

It may be sold in sheets or in narrow rolls, typically 25 or 50 mm wide, often described as "emery tape".

Emery (largely displaced by improved products such as aluminium oxide and silicon carbide) is used for scrubbing highly abraded and rough surfaces to a smooth and shiny finish, notably in watchmaking.

Both emery cloth and paper are still sold in hardware and do it yourself stores, but have been largely supplanted by the increased use of machine grinding to precision size, which has minimized or eliminated the need for hand-fitting; the widespread availability of powered hand tools employing sanding and grinding accessories such as flapwheels; and a shift to other forms of abrasive, such as aluminium oxide, aluminium zirconia and silicon carbide.

[10] Abrasive papers and cloths with a waterproof backing allow the use of a lubricant, typically water, which can both decapitate rough surfaces when used dry and produce a semi-polished satin type finish when wet.

Super-fine grades can produce a "key" adhesion surface appropriate for spray painting in critical decorative applications such as automotive bodywork repair.

Closed coat sandpaper is good for hand sanding or working with harder materials.

Other systems used in sandpaper include the Japanese Industrial Standards Committee (JIS), the micron grade (generally used for very fine grits).