Pencil

Macrophotography of the tip of a pencil.

Color pencils made with wood.

Pencils of different types.

A pencil or pencil is a writing or drawing instrument consisting of a lead or pigment stick (usually graphite) and a special grease or clay. pencil can also be colored charcoal pigment) and encapsulated usually in a fine wooden cylinder, but also in plastic, paper and metal wrappers.

A pencil that has a lead made with more clay mixed with the graphite is a sturdier pencil. They differ, on the one hand, with the letters H (from English hard = duro) and B (from English black = black), and, on the other hand, with a number from 1 to 4, number 4 being the hardest. There can also be combinations of the letters: HH, for example, refers to a very hard lead.

Modern pencils are manufactured industrially by mixing finely ground graphite powder and clay, adding water, into long leads that are fired in an oven (thermally insulated chambers). The resulting leads are dipped in oil or molten wax, which seeps into tiny holes in the material, resulting in smoother writing. A plank of wood with several long parallel grooves that is cut to form a lath, and strips of graphite and clay are inserted into the grooves. Another ribbed plank is glued on top, so the final assembly is to cut everything into individual pencils, which are then varnished or painted.

Discovery of the graphite deposit

Graphite stone.

In 1564, a huge deposit of graphite was discovered at Seathwaite Fell, near Borrowdale, Cumbria, England. Locals found it to be very useful for branding sheep. This particular deposit of graphite was extremely pure and solid, and could easily be sawn into bars. This was and remains the only large-scale deposit of graphite found in this solid form. The chemistry was in its infancy, and chemists at the time mistakenly considered the substance to be probably a form of lead; therefore, the graphite received the name plumbago (related to plumbum, "lead" in Latin). Even today the lead in a pencil is called lead in English, even though it does not contain lead. Actually, the graphite in a pencil lead is not poisonous; graphite is harmless if consumed.

The value of graphite soon became enormous, mainly because it could be used to line molds for cannonballs, and control of the mines was taken over and kept by the British Crown.

Graphite, being soft, requires a type of sheath or cover. Graphite leads were originally wrapped in twine or sheepskin to give them stability. The fame of the usefulness of these early pencils spread, attracting the attention of artists throughout the "known world".

Although graphite deposits were found in other parts of the world, they were not of the same purity and quality as those at Borrowdale, and the graphite had to be ground to powder to remove impurities. England continued to enjoy a monopoly on the production of pencils until a method of reconstituting the powder from the graphite was found. The characteristic square English pencils have continued to be made from cut sticks of natural graphite since the 1860s. Today, the town of Keswick, near the area of the original find of the graphite block, has a pencil museum.

The first attempt to make the leads with pulverized graphite was carried out in Nuremberg, Germany, in the year 1662. A mixture of graphite, sulfur and antimony was used.

Incorporation of the wooden deck

Pencil Cover: the upper sequence shows the old method, which required the graphite pieces to be cut to measure. The lower sequence is the contemporary method, using graphite strips and clay.

Italians were the first to devise a wooden support. Around 1760, the couple Simonio and Lyndiana Bernacotti were the first to create what was probably the design for the modern wood-bodied carpenter's pencil; however, their version was flat, oval, a very compact type of pencil. At first they drilled a juniper wood cylinder and then inserted the lead. Shortly after, they created an improved technique: they prepared two half-cylinders of wood, placed the lead between them, and then glued the two halves together. Essentially the same method is still in effect today.

English and German pencils were not available to the French during the Napoleonic Wars. The interest of an officer in Napoleon's army changed this situation of dependency. In 1795, Nicolas-Jacques Conté invented a method of hardening powdered graphite by mixing it with water and clay and firing it accordingly. Varying the graphite/clay ratio produced different lead hardnesses. This manufacturing method, which had previously been discovered by the Austrian Josef Hardtmuth of Koh-I-Noor in 1790, is still used today.

American colonists imported pencils from Europe until after the American Revolutionary War. Benjamin Franklin advertised pencils for sale in his Pennsylvania Gazette in 1729, and George Washington used a three-inch pencil when he explored the Ohio Territory in 1762. William Munroe, a cabinetmaker in Concord, Massachusetts, is said to have made the pencils. first American wooden pencils in 1812. This was not the only pencil factory in Concord. According to Henry Petroski, the transcendentalist philosopher Henry David Thoreau discovered how to make a good pencil out of low-quality graphite using clay as a cover; this invention was prompted by his father's pencil factory in Concord, which used graphite found in New Hampshire in 1821 by Charles Dunbar.

Munroe's method of making pencils was painstakingly slow, and in the neighboring town of Acton, a pencil mill owner named Ebenezer Wood decided to automate this process at his own pencil mill located on Nashoba Creek, along the old Davis road. For this he used the first circular saw in the production of pencils and built the first hexagonal and octagonal pencil covers that we have today. Ebenezer did not patent his invention and would share his techniques with anyone who asked. One of those was Eberhard Faber from New York who became the leader in pencil production.

Joseph Dixon, an inventor and entrepreneur involved in the Tantiusques granite quarry in Sturbridge, Massachusetts, developed a method for mass-producing pencils. Before 1870, the Joseph Dixon Crucible Company was already the world's largest authorized dealer and consumer of graphite, which would later become Dixon Ticonderoga, the contemporary supplier of pencils and art supplies.

Eraser included

Drawing the pencil with eraser at its end, your patent application.

On March 30, 1850, Hymen Lipman received the first patent for gluing an eraser to the end of a pencil. In 1862, Lipman sold his patent to Joseph Reckendorfer for $100,000, which went to sue the maker of the eraser. Faber pencil for infringement. In 1875 the Supreme Court of the United States ruled against Reckendorfer declaring the patent invalid.

Graduation and classification

Circular representation of pencil values according to hardness (9H-9B).

Two HB pencils. One graduation number 2, and another 2 1⁄2.

Many pencils around the world, and almost all in Europe, are graded using the European system that uses a continuous grading described by H (for hardness; from H]. ard = 'hard') and B (for degree of darkness; from English Black = ' black'), as well as F (for the degree of fineness; from English Fine = 'fine'). The standard pencil for writing is the HB. According to Petroski, this system would have been developed at the beginning of the 20th century by Brookman, an English manufacturer of pencils. He used the "B" for black and the "H" for hardness; the grade of a pencil was described by a sequence of successive H's and successive B's, such as BB or BBB for progressively softer leads, and HH or HHH for progressively harder leads.

Today, the pencil grading system ranges from very hard with a fine and light line, to soft with a thick and dark line, ranging from the hardest to the softest, as seen in the following table:

Koh-I-noor offers twenty graduations from 10H to 8B for its 1500 series; Derwent produces twenty graduations from 9H to 9B for its graphic pencils and Staedtler produces nineteen graduations from 9H to 8B for its Mars Lumograph pencils. The primary market for such a wide range of grades is artists, who are interested in creating a full range of shades from light gray to black. Engineers prefer harder pencils that allow more control of the lead shape. This is reflected in the way the pencils are packaged. For example, for its graphic pencils, Derwent offers three packs of 12 pencils each: Technical (hard grading 9H to B), Sketching (soft grading H to 9B), and Design (medium grading 4H to 6B).).

Pencils graded using this system are used to measure the "hardness" and the "resistance" of varnishes and paints. The resistance of a coat of varnish or paint (also known as the 'pencil hardness') is determined as the grade of the hardest pencil that does not mark the coat, when pressed firmly against the coat at a 45º angle.

Another common method uses a numerical scale to mark the graduation of a pencil. It was created by Conté and initially adopted in the United States by Thoreau in the 19th century. The following table shows the approximate equivalencies between the two systems:

*Also seen as 2-4/8, 2.5, 2-5/10. Although widely accepted, not all manufacturers use it; for example, Faber-Castell uses a different table of equivalences in its 2001 Grip pencils: 1=2B, 2=B, 2 1/2=HB, 3=H, 4=2H. For graphite pencils, the various grades of pencil are obtained by altering the ratio of graphite to clay: the more clay used, the harder the pencil. Two pencils of the same grade and from different manufacturers will not produce the same shade or necessarily have the same hardness.

Exterior colour

Color pencils.

Most pencils made in the United States are painted yellow on the outside. According to Henry Petroski, this tradition began in 1890 when the L&C Hardtmuth Company of the Austro-Hungarian Empire introduced its trademark "Koh-I- Noor", taking its name from the famous diamond. The intention was to become the best and most expensive pencil in the world and, at a time when most pencils were painted in dark colors or not at all, Koh-I-Noor's were yellow to distinguish themselves. The color 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 copied the color yellow so that their pencils would be associated with this high-quality mark, and chose brands with explicit oriental references, such as Mikado (renamed Mirado) and Mongol.

Not all countries used yellow in their pencils; German pencils, for example, are often green, based on the trademark colors of Faber-Castell, a major German stationery manufacturer.

Colored pencils (ie those with a colored lead) are usually painted on the outside the same color as the lead.

Pen Types

According to its manufacturing material

Graphite pencils

These are the most common types of pencils. They are made from a mixture of clay and graphite and their darkness ranges from light gray to black. Its composition allows smoother strokes.

Charcoal Pencils

They are made of charcoal and provide fuller blacks than graphite pencils, but they tend to smudge easily and are more abrasive than graphite. Sepia-tone and white pencils are also available for the duotone technique.

Colored pencils

Commonly known as colored pencils, they have a wax core with pigment and other additives. Multiple colors are often mixed together. The variety of a set of colored pencils can be determined by the number of unique colors it contains.

Grease pencils

Also known as China markers. They write on virtually any surface (including glass, plastic, metal, and photos). The most commonly found grease pencils are wrapped in paper (Berol and Sanford adhesives), but may also be wrapped in wood (Staedtler Omnichrom).

Watercolor pencils

These are designed for use with watercolor techniques. Pencils can be used alone for sharp and bold lines. The lines made by the pencil can also be saturated with water and extended with brushes.

According to its utility

Two wooden pencils, two carbon pencils and two fat pencils.

Carpentry pencils

These pencils have two main characteristics: their oval shape prevents them from rolling and their lead is strong. The oldest surviving pencil is a German carpenter's pencil dating to the 17th century and is now in the Faber collection -Castell and Lyra Industrial.

Copying pencils

These are graphite pencils with a dye added that creates an indelible mark. They were invented in the late 19th century for the printing press and as a practical substitute for pens. Their markings are often visually indistinguishable from those of standard graphite pencils, but when moistened their markings dissolve to a colored ink, which is then printed onto another piece of paper. It was used until the early 20th century, when the ballpoint pen slowly replaced them.

Erasable colored pencils

Unlike wax-based crayons, these can be easily erased. It is used primarily in sketching, where the goal is to create an outline using the same color that other media (such as crayons, or watercolor paints) would fill, or when the goal is to explore the color sketch. Some animators prefer erasable colored pencils to graphite pencils because these do not smudge easily, and the different colors allow for better separation of objects in the sketch. Copy-editors find them useful too, as their marks stand out more than graphite but can be erased.

Not playable

Blue non-photo pencils, such as Sanford's Copy-not or Staedtler' Mars Non-photo, or whiteprint, like Staedtler' s Mars Non-Print, they make marks that are not reproduced by photocopiers or copiers.

Stenographer's pencil

These pencils are expected to be very reliable, and their lead is break-proof. Stenographer's pencils are sometimes sharpened at both ends.

Golf pencil

So-called golf pencils are generally short (a common length is 9 cm) and very cheap. They are also known as library pencils, as many libraries offer them as non-spillable, disposable writing instruments.

According to its shape

• Triangular.
• Hexagonal.
• Rounded.
• Flexible (small plastic).
• Oval.
• Irregular.

Relevant data and others

Flexible pencils.

• The pencil has an ancestor that was the styling, which was a metal stick that the Romans used to scrape the papyrus.
• In ancient times the pencils were wrapped in animal skins. In the 18th century the wooden pencil was invented by the Italians.
• The cross-section of a pencil can be semicircular, elliptical, hexagonal or triangular.
• The first one who added a draft at the end of the pencil was Lipman in 1858.
• 18 billion pencils are manufactured per year, or 50 000 per day or 500 per second.
• If we trace a straight line with a "HB" pencil until the graphite is finished, it will have a length of 56 km.

Mechanical Pencil

Mechanical pencil mines.

There are also pencils that use mechanical methods to push the lead through a hole to the end. Erasers are also removable (and thus replaceable), and usually cover a place to store leads on top of the mechanical pencil. These types of mechanical pencils (or mechanical pencils) are popular for their longevity and the fact that they never need to be sharpened.

The types of lead are based on thickness and, like pencils, they can vary in tones and firmness, there are even colored leads. Common sizes are 0.3, 0.5, 0.7, 0.9, 1.1, 1.3, and 1.6 millimeters. The 2.0 mm size is commonly used in design, artwork, and engineering. On the other hand, the 0.5 and 0.7 leads are usually used more generally for school and office work.

It often happens that, for some brands, the leads used in mechanical pencils are too fragile, which causes them to break frequently in everyday writing, or it also happens when the artist squeezes the pencil very hard and causes a breakage. the mine, however, there are new technologies that use polymers to reinforce the structure of the mines, these being characteristics of prestigious brands. However, the stroke and the force with which a pencil is used is usually more important than the brand of the leads that are used.

Other types of pencils

• Cyrus square pencil, slightly enlarged with four colors equally distributed in the extremity. The use of each color in the drawing is achieved by turning the pencil between the fingers.
• Pie lapiz.
• Penny's pencil ^{[chuckles]required]}.
• Lapiz conté