Erase

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The Erase ( lat . Radere "to lose weight, remove, scrape scrape") describes the process of surface treatment of a solid material with the aim of its surface to remove anything. This can be part of the base material or a layer on top.

The erasing medium (the eraser) usually also consists of solid substances, which may be contained in pastes or made of knives or glass fibers. If the material is on top, the eraser's adhesive strength to these materials must be higher than to the base material. When erasing the base material, the eraser must be harder than the one.

Removal of an overlying layer

The simplest form of erasing an overlay is to remove pencil drawings or writing from paper with an eraser . The eraser, which used to be made of rubber or is now often made of plastic , mostly PVC , has a higher degree of adhesion to the carbon particles on the pencil than paper and therefore bonds faster to form crumbs that are easy to remove. Medieval painters recommended the method of etching graphite using leftover bread.

In the case of etching , this surface treatment is - in addition to the following printing technique - one aspect. This removes a layer of wax or lacquer that lies over a metal plate. During the subsequent etching, depressions are created in the metal, in which the printing ink for gravure printing adheres.

The etching by gilders and church painters also uses this method.

Removal of the base material

When erasing Indian ink or ink using a so-called fiberglass eraser or scraper knife, on the other hand, the base material (in this case paper) is removed in a thin layer by an abrasive (often pumice stone ) in order to remove the pigments lying on the paper or which have penetrated the paper. As a result, the paper naturally suffers. Even the monks of the Middle Ages copying in their writing rooms erased their ink blots with sharp blades and knives from the thinning paper. Both this process and the part of the manuscript that is edited in this way is known as shaving.

As an artistic technique, scraping is used in various scratching and scraping techniques.

The removal of ink with an ink killer , on the other hand, is based on a chemical conversion of the ink remaining in the paper, which becomes invisible as a result, but remains in the paper.

Common erasers

Other erasers and tools are:

See also