Eraser

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For other uses, see Eraser (disambiguation).
Pink erasers

An eraser (US and Canada) or rubber (India, UK, Ireland, South Africa, Australia, New Zealand and Canada) is an article of stationery that is used for removing pencil markings. Erasers have a rubbery consistency and come in a variety of shapes, sizes and colours. Some pencils have an eraser on one end. Typical erasers are made from synthetic rubber, but more expensive or specialized erasers are vinyl, plastic, or gum-like materials. Cheaper erasers can be made out of synthetic soy-based gum.

History[edit]

A pencil eraser

Before rubber erasers, tablets of rubber or wax were used to erase lead or charcoal marks from paper. Bits of rough stone such as sandstone or pumice were used to remove small errors from parchment or papyrus documents written in ink. Crustless bread was used as an eraser in the past; a Meiji-era (1868-1912) Tokyo student said: "Bread erasers were used in place of rubber erasers, and so they would give them to us with no restriction on amount. So we thought nothing of taking these and eating a firm part to at least slightly satisfy our hunger."[1]

In 1770, Edward Nairne, an English engineer, is credited with developing the first widely-marketed rubber eraser for an inventions competition. Until that time the material was known as gum elastic or by its native American name (via French) caoutchouc. Nairne sold natural rubber erasers for the high price of three shillings per half-inch cube. According to Nairne, he inadvertently picked up a piece of rubber instead of breadcrumbs, discovered rubber's erasing properties, and began selling rubber erasers. The invention was described by Joseph Priestley on April 15, 1770, in a footnote: "I have seen a substance excellently adapted to the purpose of wiping from paper the mark of black-lead-pencil. ... It is sold by Mr. Nairne, Mathematical Instrument-Maker, opposite the Royal-Exchange."[2] In 1770, the word rubber was in general use for any object used for rubbing.[3] The word became attached to the new material sometime between 1770 and 1778.[4]

However, raw rubber shared the same inconveniences as bread, since it was perishable. In 1839, inventor Charles Goodyear discovered the process of vulcanization, a method that would cure rubber and make it a durable material. Rubber erasers became common with this advent of vulcanization.

On March 30, 1858, Hymen Lipman of Philadelphia, USA, received the first patent for attaching an eraser to the end of a pencil. It was later invalidated because it was determined to be simply a composite of two devices rather than an entirely new product.[5]

Erasers may be rectangular blocks (block and wedge eraser), or conical caps that can slip onto the end of a pencil (cap eraser). A barrel or click eraser is a device shaped like a pencil, but instead of being filled with pencil lead, its barrel contains a retractable cylinder of eraser material (most commonly soft vinyl). Novelty erasers, in a dual role as figurines (such as musical notes, animals, confectionery), are mostly decorative, as their hard vinyl tends to smear heavy markings.

Types[edit]

Two kneaded erasers. A new eraser is on the left, and an older eraser on the right. The older eraser is darker due to the graphite and charcoal dust that has become incorporated into the eraser.
An electric eraser tool with replacement eraser heads
Vinyl erasers
Cap erasers.

Art gum erasers[edit]

An eraser type that is popular with artists is the art gum eraser, made of soft, coarse rubber. It is especially suited to removing large areas, and it does not damage paper. However, they are imprecise. Gum erasers tend to crumble as they are used, so this type leaves a lot of eraser residue. This residue must then be brushed away with care, as the eraser particles can leave marks on the paper. Many artists use a broad brush to sweep away the loose eraser residue. Art gum erasers are commonly tan or brown, but sometimes are sold in blue.

Kneaded erasers[edit]

Main article: Kneaded eraser

Kneaded erasers are common to most artists' standard toolkit. This type has numerous uses. They can be pulled into a point for erasing small areas and tight detail erasing, molded into a textured surface and used like a reverse stamp to give texture, or used in a "blotting" manner to lighten lines or shading without completely erasing them. They gradually lose their efficacy and resilience as they become infused with particles picked up from erasing and from their environment. They are weak at erasing large areas, as they deform under vigorous erasing.

Poster putty[edit]

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 paint, poster putty works much the same as traditional kneaded erasers, but with a greater tack or lifting strength. Poster putty does not erase so much as lighten by lifting graphite, charcoal or pastel off a drawing. In this regard, it does not smudge or damage work in progress. Repeatedly touching the putty to a drawing pulls ever more medium free, gradually lightening the work in a controlled fashion. Poster putty can be shaped into fine points or knife edges, making it ideal for detailed or painstaking work. It can be rolled across a surface to create visual textures. Poster putty loses its efficacy with use, becoming less tacky as the material grows polluted with debris and oils from the user's skin.

Electric erasers[edit]

The electric eraser has a knob on a short thin rod attached to a motor. The eraser knob turns at a uniform speed, achieving a smooth erase with a minimum of paper trauma. Electric erasers work quickly and completely.

Soft vinyl erasers[edit]

Soft vinyl has plastic texture and erases cleaner than standard erasers. They are softer and non-abrasive, making them less likely to damage canvas or paper. They are prone to cause smearing when erasing large areas or dark marks, so these erasers are used to erase light marks and for precision erasing. Engineers favor this type of eraser for work on technical drawings due to their gentleness on paper.

Other[edit]

Felt erasers are used for marks on a chalkboard or whiteboard. Rather than being rubbery or gummy like pencil erasers, they have a wooden or plastic block with a dark felt pad on one side to erase. The material in these erasers does not abrade; once they are saturated with chalk or ink, they are cleaned by clapping them against a hard surface.

Diener Industries manufactured erasers in the shape of toys. In 1955 Walt Disney contacted William Diener to ask him why souvenir pencils sold in Disneyland were not selling. Diener replied that they were overpriced but he convinced Disney they be sold with erasers in the shape of Disney characters.[6]

Erasers that are bundled on certain ballpens and permanent markers can only be used for erasing the ink of their respective writing instruments.

See also[edit]

References[edit]

  1. ^ Teiyûkai (1926). Kôbu daigakkô mukashibanashi (in Japanese). Tokyo: Teiyûkai. pp. 25–26. 
  2. ^ See the footnote on page xv at the end of the preface to the following: Priestley, Joseph (1770). A Familiar Introduction to the Theory and Practice of Perspective. London: J. John and J. Payne. 
  3. ^ Joseph Priestley (1769). A Familiar Introduction to the Study of Electricity. J. Dodsley; T. Cadell, successor to Mr. Millar; and Johnson and Payne. p. 84. 
  4. ^ R.B. Simpson (ed.), Rubber Basics, iSmithers Rapra Publishing, 2002, ISBN 185957307X, p.46 "Rubber"
  5. ^ "Reckendorfer v. Faber 92 U.S. 347 (1875)". Justia. Retrieved 2014-03-24. 
  6. ^ Cole, Benjamin Mark (August 19, 1991). "Terminating errors, promoting images: he's ... Eraserman.". Los Angeles Business Journal. Archived from the original on Oct 27, 2007. Retrieved 2014-03-24. 

Bibliography[edit]

  • Petroski, Henry (1989). The Pencil: A History of Design and Circumstance..

External links[edit]