Editing Eraser (section)

== History ==
[[File:Pencil Eraser.jpg|right|thumb|A [[pencil]] eraser]]
Before rubber erasers used today, tablets of 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; a [[Meiji period]] (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."<ref>{{cite book|author=Teiyûkai
 |title=Kôbu daigakkô mukashibanashi
 |location=Tokyo|publisher= Teiyûkai
 |year=1926|pages=25–26|language=ja}}</ref>

In 1770 English engineer [[Edward Nairne]] is reported to have developed the first widely marketed rubber eraser, for an inventions competition. Until that time the material was known as ''gum elastic'' or by its French name ''caoutchouc'' borrowed from [[Quechuan languages|Quechua]].<ref name="AoR">{{cite book |last=Loadman |first=M. J. |year=2012 |title=Analysis of Rubber and Rubber-like Polymers |url=https://www.google.com.my/books/edition/Analysis_of_Rubber_and_Rubber_like_Polym/rjD7CAAAQBAJ?hl=en&gbpv=1&dq=caa+ochu+rubber&pg=PA7&printsec=frontcover |publisher=Springer Science & Business Media |pages=6-7 |isbn=978-94-010-5905-3 }}</ref> Nairne sold natural rubber erasers for the high price of three [[shilling]]s per half-inch cube.<ref name=":0" /> 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."<ref name=":0">See the footnote on page xv at the end of the preface to the following: {{cite book | title = A Familiar Introduction to the Theory and Practice of Perspective | author = Priestley, Joseph | year = 1770 | publisher = J. John and J. Payne | location = London | url = https://archive.org/details/afamiliarintrod00conggoog| quote = A Familiar Introduction to the Theory and Practice of Perspective. }}</ref> In 1770 the word ''rubber'' was in general use for any object used for rubbing;<ref name="Priestley1769">{{cite book|author=Joseph Priestley|title=A Familiar Introduction to the Study of Electricity|url=https://books.google.com/books?id=3eFbAAAAQAAJ&pg=PA84|year=1769|publisher=J. Dodsley; T. Cadell, successor to Mr. Millar; and Johnson and Payne|page=84}}</ref> the word became attached to the new material sometime between 1770 and 1778.<ref>R.B. Simpson (ed.), ''Rubber Basics'', iSmithers Rapra Publishing, 2002, {{ISBN|185957307X}}, p.46 "Rubber"</ref>

However, raw rubber was perishable. In 1839 [[Charles Goodyear]] discovered the process of [[vulcanization]], a method that would [[Curing (chemistry)|cure]] rubber, making it durable. Rubber erasers became common with the advent of vulcanization.

On March 30, 1858, [[Hymen Lipman]] of [[Philadelphia]], United States, 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.<ref>{{cite web|url=http://supreme.justia.com/us/92/347/case.html |title=Reckendorfer v. Faber 92 U.S. 347 (1875) |publisher=Justia |access-date=2014-03-24}}</ref>

Erasers may be free-standing 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). Many, but not all, wooden pencils are made with attached erasers.{{cn|date=November 2024|reason=Citation was using a blocklisted domain}} Novelty erasers made in shapes intended to be amusing are often made of hard vinyl, which tends to smear heavy markings when used as an eraser.