2276) Pencil
Gist
A pencil is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage and keeps it from marking the user's hand.
Pencils are available in diverse types, including traditional graphite pencils, versatile mechanical pencils, and vibrant colored pencils. They continually adjust to a wide array of artistic and functional needs.
The middle ground is referred to as HB. Softer lead gets a B grading, with a number to say how soft the lead is. B on its own is just a little softer than HB. 2B, 3B and 4B are increasingly soft. Further up the range, 9B is the very softest lead available, but so soft and crumbly that it's rarely used.
The degree of hardness of a pencil is printed on the pencil.
H stands for "hard". HB stands for "hard black", which means "medium hard".
Summary
pencil, slender rod of a solid marking substance, such as graphite, enclosed in a cylinder of wood, metal, or plastic; used as an implement for writing, drawing, or marking. In 1565 the German-Swiss naturalist Conrad Gesner first described a writing instrument in which graphite, then thought to be a type of lead, was inserted into a wooden holder. Gesner was the first to describe graphite as a separate mineral, and in 1779 the Swedish chemist Carl Wilhelm Scheele showed it to be a form of carbon. The name graphite is from the Greek graphein, “to write.” The modern lead pencil became possible when an unusually pure deposit of graphite was discovered in 1564 in Borrowdale, Cumberland, Eng.
The hardness of writing pencils, which is related to the proportion of clay (used as a binder) to graphite in the lead, is usually designated by numbers from one, the softest, to four, the hardest. Artists’ drawing pencils range in a hardness designation generally given from 8B, the softest, to F, the hardest. The designation of the hardness of drafting pencils ranges from HB, the softest, to 10H, the hardest.
The darkness of a pencil mark depends on the number of small particles of graphite deposited by the pencil. The particles are equally black (though graphite is never truly black) regardless of the hardness of the lead; only the size and number of particles determine the apparent degree of blackness of the pencil mark. The degree of hardness of a lead is a measure of how much the lead resists abrasion by the fibres of the paper.
Details
A pencil is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage and keeps it from marking the user's hand.
Pencils create marks by physical abrasion, leaving a trail of solid core material that adheres to a sheet of paper or other surface. They are distinct from pens, which dispense liquid or gel ink onto the marked surface.
Most pencil cores are made of graphite powder mixed with a clay binder. Graphite pencils (traditionally known as "lead pencils") produce grey or black marks that are easily erased, but otherwise resistant to moisture, most solvents, ultraviolet radiation and natural aging. Other types of pencil cores, such as those of charcoal, are mainly used for drawing and sketching. Coloured pencils are sometimes used by teachers or editors to correct submitted texts, but are typically regarded as art supplies, especially those with cores made from wax-based binders that tend to smear when erasers are applied to them. Grease pencils have a softer, oily core that can leave marks on smooth surfaces such as glass or porcelain.
The most common pencil casing is thin wood, usually hexagonal in section, but sometimes cylindrical or triangular, permanently bonded to the core. Casings may be 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 which are not bonded to the core; instead, they support separate, mobile pigment cores that can be extended or retracted (usually through the casing's tip) as needed. These casings can be reloaded with new cores (usually graphite) as the previous ones are exhausted.
Types:
By marking material:
Graphite
Graphite pencils are the most common types of pencil, 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
Solid graphite pencils are solid sticks of graphite and clay composite (as found in a 'graphite pencil'), about the diameter of a common pencil, which have no casing other than a wrapper or label. They are often called "woodless" pencils. They are used primarily for art purposes as the lack of casing allows for covering larger spaces more easily, creating different effects, and providing greater economy as the entirety of the pencil is used. They are available in the same darkness range as wood-encased graphite pencils.
Liquid
Liquid graphite pencils are pencils that write like pens. The technology was first invented in 1955 by Scripto and Parker Pens. Scripto's liquid graphite formula came out about three months before Parker's liquid lead formula. To avoid a lengthy patent fight the two companies agreed to share their formulas.
Charcoal
Charcoal pencils 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
Carbon pencils are generally 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, are smoother than charcoal, and have minimal dust and smudging. They also blend very well, much like charcoal.
Colored
Colored pencils, or pencil crayons, have wax-like cores with pigment and other fillers. Several colors are sometimes blended together.
Grease
Grease pencils can 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).
Watercolor
Watercolor pencils are designed for use with watercolor techniques. Their cores can be diluted by water. 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.
By use:
Carpentry
Carpenter's pencils are pencils that have two main properties: their shape prevents them from rolling, and their graphite is strong. The oldest surviving pencil is a German carpenter's pencil dating from the 17th Century and now in the Faber-Castell collection.
Copying
Copying pencils (or indelible pencils) are graphite pencils with an added dye that creates an indelible mark. They were invented in the late 19th century for press copying and as a practical substitute for fountain pens. Their markings are often visually indistinguishable from those of standard graphite pencils, but when moistened their markings dissolve into a coloured ink, which is then pressed into another piece of paper. They were widely used until the mid-20th century when ball pens slowly replaced them. In Italy their use is still mandated by law for voting paper ballots in elections and referendums.
Eyeliner
Eye liner pencils are used for make-up. Unlike traditional copying pencils, eyeliner pencils usually contain non-toxic dyes.
Erasable coloring
Unlike wax-based colored pencils, the erasable variants can be easily erased. Their main use is in sketching, where the objective is to create an outline using the same color that other media (such as wax pencils, or watercolor paints) would fill or when the objective is to scan the color sketch. Some animators prefer erasable color pencils as opposed to graphite pencils because they do not smudge as easily, and the different colors allow for better separation of objects in the sketch. Copy-editors find them useful too as markings stand out more than those of graphite, but can be erased.
Non-reproduction
Also known as non-photo blue pencils, the non-reproducing types make marks that are not reproducible by photocopiers (examples include "Copy-not" by Sanford and "Mars Non-photo" by Staedtler) or by whiteprint copiers (such as "Mars Non-Print" by Staedtler).
Stenography
Stenographer's pencils, also known as a steno pencil, are expected to be very reliable, and their lead is break-proof. Nevertheless, steno pencils are sometimes sharpened at both ends to enhance reliability. They are round to avoid pressure pain during long texts.
Golf
Golf pencils are usually short (a common length is 9 cm or 3.5 in) and very cheap. They are also known as library pencils, as many libraries offer them as disposable writing instruments.
By shape:
* Triangular (more accurately a Reuleaux triangle)
* Hexagonal
* Round
* Bendable (flexible plastic)
By size:
Typical
A standard, hexagonal, "#2 pencil" is cut to a hexagonal height of 6 mm (1⁄4 in), but the outer diameter is slightly larger (about 7 mm or 9⁄32 in) A standard, "#2", hexagonal pencil is 19 cm (7.5 in) long.
Biggest
On 3 September 2007, Ashrita Furman unveiled his giant US$20,000 pencil – 23 metres (76 ft) long, 8,200 kilograms (18,000 lb) with over 2,000 kilograms (4,500 lb) for the graphite centre – after three weeks of creation in August 2007 as a birthday gift for teacher Sri Chinmoy. It is longer than the 20-metre (65 ft) pencil outside the Malaysia HQ of stationers Faber-Castell.
By manufacture:
Mechanical:
Mechanical pencils use mechanical methods to push lead through a hole at the end. These can be divided into two groups: with propelling pencils an internal mechanism is employed to push the lead out from an internal compartment, while clutch pencils merely hold the lead in place (the lead is extended by releasing it and allowing some external force, usually gravity, to pull it out of the body). The erasers (sometimes replaced by a sharpener on pencils with larger lead sizes) 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 may never need sharpening. Lead types are based on grade and size; with standard sizes being 2.00 mm (0.079 in), 1.40 mm (0.055 in), 1.00 mm (0.039 in), 0.70 mm (0.028 in), 0.50 mm (0.020 in), 0.35 mm (0.014 in), 0.25 mm (0.0098 in), 0.18 mm (0.0071 in), and 0.13 mm (0.0051 in) (ISO 9175-1)—the 0.90 mm (0.035 in) size is available, but is not considered a standard ISO size.
Pop a Point
Pioneered by Taiwanese stationery manufacturer Bensia Pioneer Industrial Corporation in the early 1970s, Pop a Point Pencils are also known as Bensia Pencils, stackable pencils or non-sharpening pencils. It is a type of pencil where many short pencil tips are housed in a cartridge-style plastic holder. A blunt tip is removed by pulling it from the writing end of the body and re-inserting it into the open-ended bottom of the body, thereby pushing a new tip to the top.
Plastic
Invented by Harold Grossman for the Empire Pencil Company in 1967, plastic pencils were subsequently improved upon by Arthur D. Little for Empire from 1969 through the early 1970s; the plastic pencil was commercialised by Empire as the "EPCON" Pencil. These pencils were co-extruded, extruding a plasticised graphite mix within a wood-composite core.
Other aspects
By factory state: sharpened, unsharpened
By casing material: wood, paper, plastic
The P&P Office Waste Paper Processor recycles paper into pencils
Health
Residual graphite from a pencil stick is not poisonous, and graphite is harmless if consumed.
Although lead has not been used for writing since antiquity, such as in Roman styli, 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.
Manufacture
The lead of the pencil is 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), 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.
