An eraser (also known as rubber in some Commonwealth countries, from the material first used) is an article of stationery that is used for removing marks from paper or skin (e.g. parchment or vellum). Erasers have a rubbery consistency and come in a variety of shapes, sizes and colours. Some pencils have an eraser on one end. Less expensive erasers are made from synthetic rubber and synthetic soy-based gum, but more expensive or specialized erasers are made from vinyl, plastic, or gum-like materials.
Read different types of pencils in Pritish Kumar blog, which are used to erase mistakes made with a pencil
At first, erasers were invented to erase mistakes made with a pencil; later, more abrasive ink erasers were introduced. The term is also used for things that remove marks from chalkboards and whiteboards.
Pencil or cap erasers
Originally made from natural rubber, but now usually from cheaper SBR, this type contains mineral fillers and an abrasive such as pumice with a plasticizer such as vegetable oil. They are relatively hard (in order to remain attached to the pencil) and frequently Colored pink. They can also be permanently attached to the end of a pencil with a ferrule.
Artist’s gum eraser
The stylized word “Art gum” was first used in 1903 and trademarked in the USA in 1907. That type of eraser was originally made from oils such as corn oil vulcanized with sulfur dichloride although may now be made from natural or synthetic rubber or vinyl compounds. It is very soft yet retains its shape and is not mechanically plastic, but crumbles as it is used. It is especially suited to cleaning large areas without damaging the paper.
High-quality plasticized vinyl or other “plastic” erasers, originally trademarked Mylar in the mid-20th century is softer, non-abrasive, and erase cleaner than standard rubber erasers. This is because the removed graphite does not remain on the eraser as much as rubber erasers, but is instead absorbed into the discarded vinyl scraps.
Kneaded erasers (called putty rubbers outside the United States) have a plastic consistency and are common to most artists’ standard toolkit. They can be pulled into a point for erasing small areas and tight detail erasing, molded into a textured surface and used as a reverse stamp to give texture, or used in a “blotting” manner to lighten lines or shading without completely erasing them.
Commonly sold in retail outlets with school supplies and home improvement products, this soft, malleable putty appears in many colors and under numerous brand names. Intended to adhere posters and prints to walls without damaging the underlying wall surface, poster putty works much the same as traditional kneaded erasers, but with a greater tack and in some circumstances, lifting strength. Poster putty does not erase so much as lighten by directly pulling particles of graphite, charcoal or pastel from a drawing.
The electric eraser was invented in 1932 by Albert J. Dremel of Racine, Wisconsin, USA. It used a replaceable cylinder of eraser material held by a chuck driven on the axis of a motor. The speed of rotation allowed less pressure to be used, which minimized paper damage. Originally standard pencil-eraser rubber was used, later replaced by higher-performance vinyl. Dremel went on to develop an entire line of hand-held rotary power tools.
A fiberglass eraser, a bundle of very fine glass fibers, can be used for erasing and other tasks requiring abrasion. Typically, the eraser is a pen-shaped device with a replaceable insert with glass fibers, which wear down in use. The fibers are very hard; in addition to removing pencil and pen markings, such erasers are used for cleaning traces on electronic circuit boards to facilitate soldering, removing rust, and many other applications.
As an example of an unusual use, a fiberglass eraser was used for preparing a Pterosaur fossil embedded in a very hard and massive limestone. Because fiberglass erasers shed fiberglass dust when used, care must be taken during and after use to avoid accidental contamination with this abrasive dust in sensitive areas of the body, especially in the eyes.
Felt chalkboard erasers or blackboard dusters are used to erase chalk markings on a chalkboard. Chalk writing leaves light-colored particles weakly adhering to a dark surface (e.g., white on black, or yellow on green); it can be rubbed off with a soft material, such as a rag. Erasers for chalkboards are made, with a block of plastic or wood, much larger than an eraser for pen or pencil, with a layer of felt on one side. The block is held in the hand and the felt rubbed against the writing, which it easily wipes off. Chalk dust is released, some of which sticks to the eraser until it is cleaned, usually by hitting it against a hard surface.
Various types of erasers, depending upon the board and the type of ink used, are used to erase a whiteboard.
Dedicated erasers that are supplied with some ballpens and permanent markers are intended only to erase the ink of the writing instrument they are made for; sometimes this is done by making the ink bond more strongly to the material of an eraser than the surface it was applied to.