Pencils create marks via physical abrasion, leaving behind a trail of solid core material that adheres to a sheet of paper or other surface. They are noticeably distinct from pens, which dispense liquid or gel ink that stain the light colour of the paper.
Most pencil cores are made of graphite mixed with a clay binder, leaving grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing, and the result is durable: although writing can usually be removed with an eraser, it is resistant to moisture, most chemicals, ultraviolet radiation and natural aging. Other types of pencil core are less widely used. Charcoal pencils are mainly used by artists for drawing and sketching. Coloured pencils are sometimes used by teachers or editors to correct submitted texts but are more usually regarded as art supplies, especially those with waxy core binders that tend to smear on paper instead of erasing. Grease pencils have a softer crayon-like waxy core that can leave marks on smooth surfaces such as glass or porcelain.
The most common type of pencil casing is a thin wooden cylinder permanently bonded around the core. Similar permanent casings may be constructed of other materials such as plastic or paper. To use the pencil, the casing must be carved or peeled off to expose the working end of the core as a sharp point. Mechanical pencils have more elaborate casings that support mobile pieces of pigment core, which can be extended or retracted through the casing tip as needed.
Pencil, from Old French pincel, a small paintbrush, from Latin penicillus a "little tail" (see penis— pincellus is Latin from the post-classical period[1]) is an artist's fine brush of camel hair, also used for writing before modern lead or chalk pencils; the meaning of "graphite writing implement" apparently evolved late in the 16th century.[2] Though the archetypal pencil was an artist's brush, the stylus, a thin metal stick used for scratching in papyrus or wax tablets, was used extensively by the Romans,[3] and for palm-leaf manuscripts.
Discovery of graphite deposit
Some time before 1565 (some sources say as early as 1500), an enormous deposit of graphite was discovered on the approach to Grey Knotts from the hamlet of Seathwaite in Borrowdale parish, Cumbria, England.[4][5][6][7] The locals found that it was very useful for marking sheep. This particular deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. This remains the only large scale deposit of graphite ever found in this solid form.[8] Chemistry was in its infancy and the substance was thought to be a form of lead. Consequently, it was called plumbago (Latin for "lead ore").[9][10] The black core of pencils is still referred to as lead, even though it never contained the element lead. The words for pencil in German (Bleistift), Irish (Peann Luaidhe), Arabic (??? ???? qalam ra?a?), and other languages literally mean lead pen.
The value of graphite was soon realised to be enormous, mainly because it could be used to line the moulds for cannonballs, and the mines were taken over by the Crown and guarded. When sufficient stores of graphite had been accumulated, the mines were flooded to prevent theft until more was required. Graphite had to be smuggled out for use in pencils. Because graphite is soft, it requires some form of encasement. Graphite sticks were initially wrapped in string or sheepskin for stability. The news of the usefulness of these early pencils spread far and wide, attracting the attention of artists all over the known world.
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. The town of Keswick, near the original findings of block graphite, still manufactures pencils, the factory also being the location of the Cumberland pencil museum.[11]
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.
Residual graphite from a pencil stick is not poisonous, and graphite is harmless if consumed
On 30 March 1858, Hymen Lipman received the first patent for attaching an eraser to the end of a pencil.[25] In 1862, Lipman sold his patent to Joseph Reckendorfer for $100,000, who went on to sue pencil manufacturer Faber-Castell for infringement.[26] In 1875, the Supreme Court of the US ruled against Reckendorfer declaring the patent invalid.[27]
Pencil extenders
Historian Henry Petroski notes that while ever more efficient means of mass production of pencils has driven the replacement cost of a pencil down, before this people would continue to use even the stub of a pencil. For those who "did not feel comfortable using a stub, pencil extenders were sold. These devices function something like a porte-crayon...the pencil stub can be inserted into the end of a shaft...Extenders were especially common among engineers and draftsmen, whose favorite pencils were priced dearly. The use of an extender also has the advantage that the pencil does not appreciably change its heft as it wears down."[20] Artists currently use extenders to maximize the use of their colored pencils.
Lead poisoning
Although lead has not been used for writing since antiquity, lead poisoning from pencils was not uncommon. Until the middle of the 20th century the paint used for the outer coating could contain high concentrations of lead, and this could be ingested when the pencil was sucked or chewed.[28]
Manufacture
Modern pencils do not contain lead as the "lead" of the pencil is actually a mix of finely ground graphite and clay powders. Before the two substances are mixed, they are separately cleaned of foreign matter and dried in a manner that creates large square cakes. Once the cakes have fully dried, the graphite and the clay squares are mixed together using water. The amount of clay content added to the graphite depends on the intended pencil hardness (lower proportions of clay makes the core softer),[29] and the amount of time spent on grinding the mixture determines the quality of the lead. The mixture is then shaped into long spaghetti-like strings, straightened, dried, cut, and then tempered in a kiln. The resulting strings are dipped in oil or molten wax, which seeps into the tiny holes of the material and allows for the smooth writing ability of the pencil. A juniper or incense-cedar plank with several long parallel grooves is cut to fashion a "slat," and the graphite/clay strings are inserted into the grooves. Another grooved plank is glued on top, and the whole assembly is then cut into individual pencils, which are then varnished or painted. Many pencils feature an eraser on the top and so the process is usually still considered incomplete at this point. Each pencil has a shoulder cut on one end of the pencil to allow for a metal ferrule to be secured onto the wood. A rubber plug is then inserted into the ferrule for a functioning eraser on the end of the pencil
Modern pencils do not contain lead as the "lead" of the pencil is actually a mix of finely ground graphite and clay powders. Before the two substances are mixed, they are separately cleaned of foreign matter and dried in a manner that creates large square cakes. Once the cakes have fully dried, the graphite and the clay squares are mixed together using water. The amount of clay content added to the graphite depends on the intended pencil hardness (lower proportions of clay makes the core softer),[29] and the amount of time spent on grinding the mixture determines the quality of the lead. The mixture is then shaped into long spaghetti-like strings, straightened, dried, cut, and then tempered in a kiln. The resulting strings are dipped in oil or molten wax, which seeps into the tiny holes of the material and allows for the smooth writing ability of the pencil. A juniper or incense-cedar plank with several long parallel grooves is cut to fashion a "slat," and the graphite/clay strings are inserted into the grooves. Another grooved plank is glued on top, and the whole assembly is then cut into individual pencils, which are then varnished or painted. Many pencils feature an eraser on the top and so the process is usually still considered incomplete at this point. Each pencil has a shoulder cut on one end of the pencil to allow for a metal ferrule to be secured onto the wood. A rubber plug is then inserted into the ferrule for a functioning eraser on the end of the pencil.[30]
Grading and classification
"Pencil hardness" redirects here.
HB graphite pencils. One is labelled #2 and the other #21/2
A grading chart ranging from 9B to 9H
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", a letter arbitrarily chosen to indicate midway between HB and H. (It is a persistent myth that "F" stands for "Fine"; grade F pencils are no more fine or easily sharpened than any other grade). The standard writing pencil is graded HB.[citation needed] According to Petroski, this system might have been developed in the early 20th century 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.[31]
As of 2009, 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:
9H 8H 7H 6H 5H 4H 3H 2H H F HB B 2B 3B 4B 5B 6B 7B 8B 9B
Hardest ? Medium ? Softest
Koh-i-noor offers twenty grades from 10H to 8B for its 1500 series;[32] Mitsubishi Pencil offers twenty-two grades from 10H to 10B for its Hi-uni range;[33] Derwent produces twenty grades from 9H to 9B for its graphic pencils[34] and Staedtler produces nineteen from 9H to 8B for its Mars Lumograph pencils.[35]
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).[citation needed]
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.[36][37]
Conté/Thoreau[38]
Tone US World
#1 B
#2 HB
#21/2 * F
#3 H
#4 2H
* Also seen as 2-4/8, 2.5, 2-5/10
Another method uses numbers to designate the grade of a pencil. It was originally created by Conté and adopted in the US by John Thoreau, father of Henry Thoreau, in the 19th century.[39]
Although Conté/Thoreau's system is 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, 21/2 = 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.[40][41][42] 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 US are painted yellow.[44] According to Henry Petroski,[45] 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)[46][47] and Mongol.[48][49]
Not all countries use yellow pencils. German and Brazilian pencils, for example, are often green, blue or black, based on the trademark colours of Faber-Castell, a major German stationery company which has plants in those countries. In southern European countries, pencils tend to be dark red or black with yellow lines, while in Australia, they are red with black bands at one end. In India, the most common pencil colour scheme was dark red with black lines, and pencils with a large number of colour schemes are produced by various companies.
Pencils are commonly round, hexagonal, or sometimes triangular in section. Carpenters' pencils (see below) are typically oval or rectangular, so they cannot easily roll away during work.
Notable pencil users
Thomas Edison had his pencils specially made by Eagle Pencil. Each pencil was three inches long, was thicker than standard pencils and had softer graphite than was normally available.[21]
Vladimir Nabokov rewrote everything he had ever published, usually several times, by pencil.[21]
John Steinbeck was an obsessive pencil user and is said to have used as many as 60 a day. His novel East of Eden took more than 300 pencils to write.[21]
Vincent van Gogh used only Faber pencils as they were "superior to Carpenters pencils, a capital black and most agreeable".[21][50]
Johnny Carson regularly played with pencils at his Tonight Show desk. These pencils were specially made with erasers at both ends to avoid on-set accidents.[51]
Roald Dahl used only pencils with yellow casing to write his books. He had 6 sharpened pencils ready at the beginning of each day and only when all 6 pencils became unusable did he resharpen them.[citation needed]
Types
By marking material
Coloured pencils
Promotional pencils
Graphite pencils
These are the most common types of pencils, and are encased in wood. They are made of a mixture of clay and graphite and their darkness varies from light grey to black. Their composition allows for the smoothest strokes.
Solid graphite pencils
As the name implies, these are solid sticks of graphite, about the diameter of a common pencil, which have no casing. They are often called "woodless" pencils. They are used primarily for art purposes as the lack of casing allows for covering larger spaces easier, creating different effects, and providing for more economy as the entirety of the pencil is used up. They are available in the same darkness range as wood-encased graphite pencils.
Charcoal pencils
They are made of charcoal and provide fuller blacks than graphite pencils, but tend to smudge easily and are more abrasive than graphite. Sepia-toned and white pencils are also available for duotone techniques.
Carbon pencils
They generally are made of a mixture of clay and lamp black, but are sometimes blended with charcoal or graphite depending on the darkness and manufacturer. They produce a fuller black than graphite pencils, but are smoother than charcoal.
Coloured pencils, or pencil crayons
These have wax-like cores with pigment and other fillers. Multiple colours are often blended together.[52]
Grease pencils
They write on virtually any surface (including glass, plastic, metal and photographs). The most commonly found grease pencils are encased in paper (Berol and Sanford Peel-off), but they can also be encased in wood (Staedtler Omnichrom).[52]
Watercolour pencils
These are designed for use with watercolour techniques. The pencils can be used by themselves for sharp, bold lines. Strokes made by the pencil can also be saturated with water and spread with brushes.[52
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