Editing Eraser (section)

===Artist's gum eraser===
The stylized word "Art gum" was first used in 1903 and trademarked in the United States in 1907.<ref>Reg. No. 60496 & No. 435240, ''ERASERS OR ELASTIC COMPOSITIONS FOR ERASING MARKS FROM AND CLEANING DRAWINGS, TRACINGS, PICTURES'' [http://tmsearch.uppto.gov]{{dead link|date=September 2017|bot=InternetArchiveBot|fix-attempted=yes}}</ref> That type of eraser was originally made from oils such as [[corn oil]] [[vulcanized]] with [[sulfur dichloride]]<ref>US patent 2676160</ref> although it 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. However, they are so soft as to be imprecise in use. The removed graphite is carried away in the crumbles, leaving the eraser clean, but resulting in a lot of eraser residue. This residue must then be brushed away with care, as the eraser particles are coated with the graphite and can make new marks.  Art gum erasers are traditionally tan or brown, but some are blue.