A pencil is a writing or drawing instrument consisting of a thin stick of pigment (usually graphite, but can also be coloured pigment or charcoal) and clay, usually encased in a thin wood cylinder, though paper and plastic sheaths are also used. Pencils are distinct from pens, which use a liquid marking material.
The archetypal pencil may have been the stylus, which was a thin metal stick, often made from lead and used for scratching on papyrus, a form of early paper. They were used extensively by the ancient Egyptians and Romans. The word pencil comes from the Latin word pencillus which means "little tail."
The value of graphite was soon realized to be enormous, mainly because it could be used to line the moulds for cannon balls, and the mines were taken over by the Crown and guarded. Graphite had to be smuggled out for use in pencils. Because graphite is soft, it requires some form of case. Graphite sticks were at first wrapped in string or in sheepskin for stability. The news of the usefulness of these early pencils spread far and wide, attracting the attentions of artists all over the "known world."
Although deposits of graphite had been found in other parts of the world, they were not of the same purity and quality as the Borrowdale find, and had to be crushed to remove the impurities, leaving only graphite powder. England continued to enjoy a monopoly on the production of pencils until a method of reconstituting the graphite powder was found. The distinctively square English pencils continued to be made with sticks cut from natural graphite into the 1860s. Today, the town of Keswick, near the original findings of block graphite, has a pencil museum. The first attempt to manufacture graphite sticks from powdered graphite was in Nuremberg, Germany, in 1662. It used a mixture of graphite, sulphur, and antimony.
English and German pencils were not available to the French during the Napoleonic wars; France, under naval blockade imposed by Great Britain, was unable to import the pure graphite sticks from the British Seathwaite Fell mines - the only known source in the world for solid graphite. France was also unable to import the inferior German graphite pencil substitute. It took the efforts of an officer in Napoleon's army to change this. In 1795 Nicholas Jacques Conté discovered a method of mixing powdered graphite with clay and forming the mixture into rods that were then fired in a kiln. By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied. This method of manufacture which had been earlier discovered by the Austrian Joseph Hardtmuth of Koh-I-Noor in 1790 remains in use.
American colonists imported pencils from Europe until after the American Revolution. Benjamin Franklin advertised pencils for sale in his Pennsylvania Gazette in 1729, and George Washington used a three-inch pencil when he surveyed the Ohio Territory in 1762. It is said that William Munroe, a cabinetmaker in Concord, Massachusetts, made the first American wood pencils in 1812. This was not the only pencil-making in Concord. According to Henry Petroski, transcendentalist philosopher Henry David Thoreau discovered how to make a good pencil out of inferior graphite using clay as the binder; this invention was prompted by his father's pencil factory in Concord, which employed graphite found in New Hampshire in 1821 by Charles Dunbar.
Munroe's method of making pencils was painstakingly slow, and in the neighbouring town of Acton, a pencil mill owner named Ebenezer Wood set out to automate the process at his own pencil mill located at Nashoba Brook along the old Davis Road. He used the first circular saw in pencil production. He constructed the first hexagon- and octagon-shaped pencil cases that we have today. Ebenezer did not patent his invention and shared his techniques with whoever asked. One of those was Eberhard Faber of New York, who became the leader in pencil production.
Joseph Dixon, an inventor and entrepreneur involved with the Tantiusques granite mine in Sturbridge, Massachusetts, developed a means to mass produce pencils. By 1870, The Joseph Dixon Crucible Company was the world’s largest dealer and consumer of graphite and later became the contemporary Dixon Ticonderoga pencil and art supplies company.
Many pencils across the world and almost all in Europe are graded on the European system using a continuum from "H" (for hardness) to "B" (for blackness), as well as "F" (for fine point). The standard writing pencil is graded HB. According to Petroski this system might have been developed in the early 1900s by Brookman, an English pencil maker. It used "B" for black and "H" for hard; a pencil's grade was described by a sequence or successive Hs or Bs such as BB and BBB for successively softer leads, and HH and HHH for successively harder ones.
Today a set of pencils ranging from a very hard, light-marking pencil to a very soft, black-marking pencil usually ranges from hardest to softest as follows.
Koh-i-noor offers twenty grades from 10H to 8B for its 1500 series; Derwent produces twenty grades from 9H to 9B for its Graphic pencils and Staedtler produces nineteen from 9H to 8B for its Mars Lumograph pencils. The main market for such wide range of grades are artists who are interested in creating a full range of tones from light grey to black. Engineers prefer harder pencils which allow for a greater control in the shape of the lead. This is reflected in the way pencils are packaged and marketed. For example, for its Graphic pencils Derwent offers three packages of 12 pencils each: Technical (with hard grades from 9H to B), Sketching (with soft grades H to 9B), and Designer (with medium grades 4H to 6B).
Pencils graded using this system are used to measure the hardness and resistance of varnishes and paints. The resistance of a coating (also known as its pencil hardness) is determined as the grade of the hardest pencil that does not mark the coating when pressed firmly against it at a 45 degree angle.
Another common method uses numbers to designated the grade of a pencil. It was originally created by Conté and adopted in the United States by Thoreau in the 19th century. The following table shows approximate equivalences between the different systems:
* Also seen as 2-4/8, 2.5, 2-5/10. Although widely accepted, not all manufacturers follow it; for example, Faber-Castell uses a different equivalence table in its Grip 2001 pencils: 1=2B, 2=B, 2 1/2=HB, 3=H, 4=2H.
The various graphite pencil grades are achieved by altering the proportion of graphite to clay: the more clay the harder the pencil. Two pencils of the same grade but different manufacturers will not necessarily make a mark of identical tone nor have the same hardness.
The majority of pencils made in the United States are painted yellow. According to Henry Petroski, this tradition began in 1890 when the L. & C. Hardtmuth Company of Austria-Hungary introduced their Koh-I-Noor brand, named after the famous diamond. It was intended to be the world's best and most expensive pencil, and at a time when most pencils were either painted in dark colours or not at all, the Koh-I-Noor was yellow. As well as simply being distinctive, the colour may have been inspired by the Austro-Hungarian flag; it was also suggestive of the Orient, at a time when the best-quality graphite came from Siberia. Other companies then copied the yellow colour so that their pencils would be associated with this high-quality brand, and chose brand names with explicit Oriental references, such as Mikado (renamed Mirado) and Mongol.
Not all countries use yellow pencils; however, German pencils, for example, are often green, based on the trademark colours of Faber-Castell, a major German stationery company. Pencils are commonly round, hexagonal or sometimes triangular in section.
There are also pencils which use mechanical methods to push lead through a hole at the end. The erasers are also removable (and thus replaceable), and usually cover a place to store replacement leads. Mechanical pencils are popular for their longevity and the fact that they never need sharpening.
Lead types are based on thickness. Common sizes are 0.3, 0.5, 0.7, 0.9, 1.1, and 1.6 millimetres. The 2.0 mm size is commonly used in designing, artwork, and engineering, but is not commonly used outside these fields due to its high cost.