From Encyclopedia Jr, free information reference for Kids
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For other uses, see Eraser (disambiguation).
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 eraser (American English), primarily known as a rubber in British and Commonwealth English, is an article of stationery that is used for removing pencil and sometimes pen writings. Erasers have a rubbery consistency, and they are often white, brown or pink although with modern materials they can be any color at all. Many pencils are equipped with an eraser on one end. Typical erasers are made of rubber, but more expensive or specialized erasers can also contain vinyl, plastic, or gum-like materials.
[edit] Types
A variety of specialized erasers are manufactured today. The type of eraser often attached to pencils is usually pink or red, and has a smooth, rubbery texture. It is good for most erasing purposes, though it tends to smear and can damage the paper if used too heavily. It leaves eraser residue that must be brushed away; care must be taken in brushing away residue, as the eraser particles can leave marks on the paper.
Another 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 does not damage the paper. This eraser leaves a lot of eraser residue, however, and is not very precise. Art gum erasers are commonly tan or brown.
The kneaded eraser (or kneaded rubber eraser) is also well-known among artists. It is usually made of a grey or white pliable material that resembles putty or gum. It functions by "absorbing" and "picking up" graphite and charcoal particles. It does not wear away and leave behind eraser residue, thus it lasts much longer than other erasers. Kneaded erasers can be shaped with the fingers and used for precision erasing, to create highlights, or for detailing work. It is commonly used to remove light charcoal and light graphite marks in subtractive drawing techniques. However, it is not well-suited to completely erasing large areas, and may smear or stick if it becomes too warm. Though it does not wear away like other erasers but it can become exhausted, unable to absorb any more graphite or charcoal in which case it will start to smear and actually make marks instead of erasing them.
Soft vinyl erasers have a plastic-like texture and erase cleaner than standard pink erasers. They are somewhat softer, therefore less likely to damage canvas or paper. Vinyl erasers are commonly white.
Erasers come in several shapes and sizes. In addition to those that come attached to pencils, they may also be rectangular blocks (block or 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. Novelty erasers are made in a wide variety of shapes, colors, and designs to suit their themes (such as musical notes, animals, confectionery), and they are typically acquired more for their decorative nature than for any practical use.
[edit] History
Prior to using rubber, white bread (without crust) was used to erase the mark of graphite pencil and charcoal. It is still sometimes used for that by charcoal artists.
In 1770, scientist Joseph Priestley noted, "I have seen a substance excellently adapted to the purpose of wiping from paper the mark of black lead pencil."
Also in 1770, Edward Naime, an English engineer, is credited with creating the first rubber eraser, and reportedly was selling natural rubber erasers for the astonishingly high price of 3 shillings per half-inch cube. According to Naime himself, he inadvertently picked up a piece of rubber instead of breadcrumbs, discovered rubber's erasing properties, and began selling rubber erasers. Incidentally, this was the first practical application of the substance in Europe, and rubbing out the pencil marks gave it its English name.
However, rubber in its raw form shared the same inconveniences as bread, since it was perishable and would go bad over time. 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 vulcanized rubber.
On March 30, 1858, Hymen Lipman of Philadelphia, Pennsylvania, 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.
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