A pencil or pen is a writing or drawing instrument consisting of a thin stick of pigment (usually graphite and a fat or special clay, but can also be colored pigment charcoal) and usually encapsulated in a cylinder fine wood, though paper and plastic wraps are also used. Pencils are distinct from pens, as they use a liquid material marker. pencil Source:
since before 1665 (some sources say since 1600), a large graphite deposit was discovered at Seathwaite Fell near Borrowdale, Cumbria, England. The locals found it useful for marking sheep. This particular deposit of graphite was extremely pure and solid, and could easily be sawn into sticks. Graphite, being soft, it requires a type of hull or deck. Graphite sticks, at first, were wrapped in string or in sheepskin for stability. The fame of the usefulness of these early pencils spread, attracting the attention of artists all over the known world. England continued to enjoy a monopoly in the production of pencils until he found a method of reconstituting the graphite powder. The distinctive square English pencils continue to be made with sticks cut from graphite natural desde 1860. Hoy, la ciudad de Keswick, cercana a la zona del hallazgo original del bloque de grafito, tiene un museo del lápiz.
La primera tentativa de fabricar los palillos del grafito pulverizado se llevó a cabo en Núremberg, Alemania, en 1662. Se utilizó una mezcla de grafito, sulfuro, y antimonio. El grafito residual de un palillo de lápiz no es venenoso; el grafito es inofensivo si se consume.
Fueron los italianos los primeros en idear la sujeción de madera. Una pareja de italianos, Simonio y Lyndiana Bernacotti, fueron los primeros que crearon diseños para el lápiz moderno de carpintería con el fin de marcar sus piezas de madera; sin embargo, su versión era chata, ovalada, un more compact type of pencil. They did this at first cupping a stick of juniper wood. Soon after they created an improved technique: the two halves of wood carved, a graphite stick inserted, and then the two halves were attached, essentially the same method is still valid 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 that. In 1795 Nicholas Jacques Conté discovered the method of mixing powdered graphite with clay, forming the mixture into rods which were then fired in a kiln. By varying the proportion of graphite with clay is defined The hardness of graphite. This manufacturing method that had been discovered earlier by the Austrian Josef Hardtmuth Koh-I-Noor in 1790 remains in use today. Draft
included:
March 30, 1858, Hymen Lipman received the first patent for hitting a draft to the end of a pencil. In 1862 Lipman sold his patent to Joseph Reckendorf for $ 100,000, which were intended to sue the pencil manufacturer Faber for infringement. In 1875 the Supreme Court ruled against the United States Reckendorf declaring the patent to be invalid.
Manufacture:
modern pencils are made industrially by mixing powder grafito y arcilla molidos finamente, agregando agua, formando tiras largas como espagueti, y encendiéndolas en un horno (compartimientos térmicamente aislados). Las tiras resultantes se sumergen en aceite o cera fundida, que filtra en los agujeros minúsculos del material, dando por resultado una escritura más lisa. Un tablón de enebro o de cedro de incienso con varios surcos paralelos largos se corta para formar un listón, y las tiras de grafito y arcilla se insertan en los surcos. Otro tablón acanalado se pega encima, de manera que el ensamble final es cortar todo en lápices individuales, que luego se barnizan o se pintan.
Graduación y clasificación:
Muchos lápices a través the world, and almost all in Europe, are classified with the European system that uses a continuous gradation described by "H" (for hardness) and "B" (for blackness), and "F" (p
o the degree of fineness). The standard writing pencil is HB. According to Petroski, the system would have developed in the early twentieth century by Brookman, an English manufacturer of pencils. Used the "B" for black and "H" for the hardness, the degree of a pencil is described by a sequence of successive H and B in succession, such as BB or BBB for mining increasingly smooth, and HH or HHH mining increasingly tough. Today, the classification system pencil extending from very hard with thin and clear, bold to soft and dark, ranging from harder to softer, as shown in the following example:
| | | | | | | | | | | | | | | | | | | | |
| 9H 8H 7H | 6H 5H 4H | 3H 2H H | F | B HB 2B | 3B 4B 5B | 6B 7B 8B | 9B | ||||||||||||
| → Middle → | Soft | ||||||||||||||||||
Koh-I-noor offers twenty rankings 10H to 8B for its 1500 series; Derwent produces twenty rankings 9H to 9B for your pencils gráficos y Staedtler produce diecinueve de 9H a 8B para sus lápices de Mars Lumograph. El mercado principal para tan amplia gama de grados es el de los artistas, que están interesados en crear una gama completa de tonos de gris claro a negro. Los ingenieros prefieren lápices más duros que permitan un mayor control de la forma de la mina. Esto se refleja en la manera en que se empaquetan los lápices. Por ejemplo, para sus lápices gráficos, Derwent ofrece tres paquetes de 12 lápices cada uno: Técnico (graduación dura de 9H a B), para bosquejos (graduación suave de H a 9B), y de diseño (con graduación media de 4H a 6B). Los lápices classified within this system is used to measure the hardness and resistance of varnishes and paints. The resistance of a layer of varnish or paint (also known as the "pencil hardness) is determined as the hardest pencil grade that does not mark the coating when it is pressed firmly against the layer at an angle of 45 degrees.
Another common method uses numbers to mark the graduation of a pencil. It was created by Conté and adopted initially in the United States by Thoreau in the nineteenth century. The following table shows the approximate equivalence between the two systems:
| Tone | USA | | World |
|---|---|---|---|
| | # 1 | = | B |
| | # 2 | = | HB |
| | # 2 ½ * | = | F |
| | # 3 | = | H |
| | # 4 = 2H |
* Also seen as 2-4 / 8, 2.5, 2-5/10. Even if they are accepted widely, not all manufacturers use it, for example, Faber-Castell uses a different table of equivalences in Grip 2001 pencils: 1 = 2B, 2 = B, 2 1 / 2 = HB, 3 = H, 4 = 2H. For pencils, pencil varying degrees are obtained by altering the proportion of graphite and clay: the more clay is used, the harder the pencil. Two pencils of the same grade and from different manufacturers will not produce the same tone or necessarily have the same hardness. Types
pencil
According to material manufacturing
graphite pencils
Here are the most common types of pencils. They are made of a mixture of clay and graphite and its darkness varies from light gray to black. Your membership ensures smooth strokes.
charcoal pencils
are made of charcoal and black provide fuller than graphite pencils, but tend to stain easily and are more abrasive than graphite. The sepia tone pencils and white are also available for duotone technique.
crayon pencils
commonly known as colored pencils, they have a center of wax with pigment and other additives. Multiple colors are often mixed together. The range of a set of crayon pencils can be determined by the number of unique colors in it.
grease pencils
also known as China markers. They write on virtually any surface (including glass, plastic, metal and photographs). Grease pencils are most commonly found wrapped in paper (Berol Sanford and adhesives), but may also be involved in wood (Staedtler Omnichrom).
Watercolor Pencils
These are designed for use with watercolor techniques. Pencils can be used alone to the sharp lines and bold. Strokes made by the pen can also be saturated with water and spread with brushes.
According to its utility
carpenter pencils
These pencils have two main characteristics: their shape prevents them rolling, and mine is strong. The older pen that remains is a carpenter pencil German dating back to XVII century and now is in the collection of Faber-Castell.
copying pencils
These are pencils with a dye added it creates an indelible mark. They were invented in the late nineteenth century printing press and as a practical substitute for feathers. Their markings are often visually indistinguishable from those of standard graphite pencils, but when wet its brands dissolve at a colored ink, which is then printed another piece of paper. It was used until the early twentieth century, when the pen slowly replaced them.
erasable color pencils
Unlike pencils wax-based color they can be easily erased. It is primarily used in drafts, where the goal is to create a schema using the same color as other means (such as crayons or watercolor paints) would fill, or when the objective is to explore the outline color. Some animators prefer erasable colored pencils to graphite pencils because they do not stain easily, and the different colors allow for better separation of objects in the sketch. Copy-editors find them useful too, as their brands stand out more than graphite but can be erased.
not reproducible
Or Non-photo blue pencils make marcas que no son reproducidas por las fotocopiadoras (Sanford's Copy-not o Staedtler' Mars Non-photo) o por las copiadoras whiteprint (Staedtler' s Mars Non-Print).
Lápiz de estenógrafo
Se espera que estos lápices sean muy confiables, y su mina es a prueba de roturas. Los lápices del estenógrafo se afilan a veces en ambos extremos
Lápiz de golf
Los lápices de golf son generalmente cortos (una longitud común es los 9cm) y muy baratos. También se conocen como lápices de biblioteca, ya que muchas bibliotecas los ofrecen como instrumentos de escritura desechables e inderramables.
Según as
- Triangular Rounded Hexagonal
- Flexible (plastic malleable)
