"It is formed in the sea by sub-microscopic plankton, which fall to the sea floor and are then consolidated and compressed during diagenesis into chalk rock. Most people first encounter the word ""chalk"" in school where it refers to blackboard chalk, which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased. Blackboard chalk manufacture now may utilize mineral chalk, other mineral sources of calcium carbonate, or the mineral gypsum (calcium sulfate). While gypsum-based blackboard chalk is the lowest cost to"
"Blackboard A blackboard (also known as a chalkboard) is a reusable writing surface on which text or drawings are made with sticks of calcium sulfate or calcium carbonate, known, when used for this purpose, as chalk. Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone. A blackboard can simply be a board painted with matte dark paint (usually black, occasionally dark green). Matte black plastic sign material (known as ‘closed-cell PVC foamboard’) is also used to create custom chalkboard art. A more modern variation consists of a coiled sheet of plastic drawn across two"
"Chalk on a black-Board”. The first attested use of chalk on blackboard in the United States dates to September 21, 1801, in a lecture course in mathematics given by George Baron. James Pillans has been credited with the invention of coloured chalk (1814): he had a recipe with ground chalk, dyes and porridge. The use of blackboard did change methods of education and testing, as found in the Conic Sections Rebellion of 1830 in Yale. Blackboard A blackboard (also known as a chalkboard) is a reusable writing surface on which text or drawings are made with sticks of calcium sulfate"
"Chalkboard paint Chalkboard paint is a specialized paint that creates a chalkboard like coating that can be utilized as a writing surface in the same manner as a traditional chalkboard or blackboard. Chalkboard paint is commonly made out of a mixture of talc, acrylic, water, glycol, titanium dioxide, carbon black, opacifiers, silica, and esters. It may also contain acetone, propane, butane, xylene, ethylbenzene, amorphous silica, n-butyl acetate, and propylene glycol methyl ether acetate which are industrial standard ingredients used in inks and paints as thinners, olfactory, and pigmentation agents. Chalkboard paint should not be confused with chalk paint which is"
"then moves them out of reach, allowing a large amount of material to be shown simultaneously. The chalk marks can be easily wiped off with a damp cloth, a sponge or a special blackboard eraser usually consisting of a block of wood covered by a felt pad. However, chalk marks made on some types of wet blackboard can be difficult to remove. Blackboard manufacturers often advise that a new or newly resurfaced blackboard be completely covered using the side of a stick of chalk and then that chalk brushed off as normal to prepare it for use. Sticks of processed"
"Chalkboard eraser A chalkboard eraser (or blackboard duster) is a special type of eraser specifically used to erase chalk markings on slating paint (used on chalkboards and slates). It is most commonly made of felt strips attached to an ergonomically designed handle. Chalkboard erasers were first invented around 1863 by John L. Hammett, who owned some stores that sold and created school products in Rhode Island and then later in Boston. Mostly slates were sold there as well as chalk and so on. At the time, rags or old cloths were used to erase and get rid of the chalk"
"Chalkboard eraser A chalkboard eraser (or blackboard duster) is a special type of eraser specifically used to erase chalk markings on slating paint (used on chalkboards and slates). It is most commonly made of felt strips attached to an ergonomically designed handle. Chalkboard erasers were first invented around 1863 by John L. Hammett, who owned some stores that sold and created school products in Rhode Island and then later in Boston. Mostly slates were sold there as well as chalk and so on. At the time, rags or old cloths were used to erase and get rid of the chalk"
"a paint invented by Annie Sloan that provides a matted appearance to the coated surfaces. Chalkboard paint Chalkboard paint is a specialized paint that creates a chalkboard like coating that can be utilized as a writing surface in the same manner as a traditional chalkboard or blackboard. Chalkboard paint is commonly made out of a mixture of talc, acrylic, water, glycol, titanium dioxide, carbon black, opacifiers, silica, and esters. It may also contain acetone, propane, butane, xylene, ethylbenzene, amorphous silica, n-butyl acetate, and propylene glycol methyl ether acetate which are industrial standard ingredients used in inks and paints as thinners,"
"Sidewalk chalk Sidewalk chalk is typically large colored (and sometimes white or cream) sticks of chalk (calcium sulfate rather than rock chalk, calcium carbonate) mostly used for drawing on pavement or concrete sidewalks. It is sometimes used by children to draw a four square court or a hopscotch board. Blackboard chalk is typically shorter. There are several different types of sidewalk chalk, typically coming in solid-colored sticks. 3-D sidewalk chalk sets, in which each stick of chalk is created with two particular colors that appear 3-dimensional when viewed through the 3-D glasses that come with the chalk, also exist. Sidewalk"
"Chalk talk A chalk talk is a monologue presentation done while the speaker draws. It is usually done with chalk, hard crayon, or pastel, or with dry-erase markers on a whiteboard. The chalk talk method of teaching focuses on the blackboard and the lecturer's voice and also the activities – to be precise, the physical activities. This method can be preferred for presenting lectures and talks. Because of an article in the ""Deseret News"" published on September 17, 1895 the roots of ""chalk talks"" can be traced to the Methodist church - and a singular individual - Mr. Frank Beard"
"parallel rollers, which can be scrolled to create additional writing space while saving what has been written. The highest grade blackboards are made of a rougher version porcelain enamelled steel (black, green, blue or sometimes other colours). Porcelain is very hard wearing and blackboards made of porcelain usually last 10–20 years in intensive use. Manufacturing of slate blackboards began by the 1840s. Green chalkboards, generally made of porcelain enamel on a steel base, first appeared in the 1960s. Lecture theatres may contain a number of blackboards in a grid arrangement. The lecturer then moves boards into reach for writing and"
"to the American Academy of Allergy, Asthma and Immunology (AAAAI), there are links between chalk dust and allergy and asthma problems. The dust also precludes the use of chalk in areas shared with dust-sensitive equipment such as computers. The writing on blackboards is difficult to read in the dark. Chalk sticks shrink through use, and are notorious for breaking in half unless inserted in a writing utensil designed for chalk. The scratching of fingernails on a blackboard, as well as other pointed, especially metal objects against blackboards, produces a sound that is well known for being extremely irritating to most"
"a lead-based metal alloy that leaves dark markings on paper by abrading small pieces of core onto the surface. However, most modern ""lead pencils"" have a nonpoisonous core of greyish-black graphite mixed with various proportions of clay for consistency, enclosed within an outer wooden casing to protect the fragile graphite from being snapped apart or from leaving marks on the user's hand. White chalk has been traditionally used in schoolrooms to write on a main blackboard at the front of the room. In the 19th century, and indeed well into the 20th century, when paper was less readily available, individual"
"hammers, tape measures and chalk. The ""chalk"" is actually a small pre-cut block of talc (soapstone). These talc blocks can be sharpened to a stronger point than the softer blackboard chalk. The color of the chalk provides good contrast against the dark color of the hot rolled steel that is generally used. In carpentry and joinery practice a pencil is used for marking while in cabinetmaking a marking knife provides for greater accuracy. A storey pole is used to lay out repeated measurements such as the location of joints in timber framing, courses of siding such as wood shingles and"
"mountain"" in Hawaiian, Mont Blanc means ""white mountain"" in French. Changbai Mountains literally meaning ""perpetually white mountains"", marks the border between China and Korea. Chalk is a kind of limestone, made of the mineral calcite, or calcium carbonate. It was originally deposited under the sea as the scales or plates of tiny micro-organisms called Coccolithophore. It was the first white pigment used by prehistoric artists in cave paintings. The chalk used on blackboards today is usually made of gypsum or calcium sulphate, a powder pressed into sticks. ""Bianco di San Giovanni"" is a pigment used in the Renaissance, which was"
"are made up of shorter pieces of wood ""finger jointed"" together with an adhesive. In North America clapboards were historically made of split oak, pine and spruce. Modern clapboards are available in red cedar and pine. In some areas, clapboards were traditionally left as raw wood, relying upon good air circulation and the use of 'semi-hardwoods' to keep the boards from rotting. These boards eventually go grey as the tannins are washed out from the wood. More recently clapboard has been tarred or painted—traditionally black or white due to locally occurring minerals or pigments. In modern clapboard these colors remain"
"easier to scratch into for cleaner, crisper details and lines. Several tools have been created specifically for scratchboard; however any sharp implement will do though a range of blades of different thicknesses allows the removal of more or less of the ink at will (see variety of tools listed below). Isopropyl Alcohol on a cotton swab or cotton ball, sandpaper and non-oily, fine, steel wool are also useful for removing large areas, and creating texture. Coloring scratchboard, black or white boards, can be done with many media applied with paint brush, air brush, and even cotton balls. Special scratchboard colored"
"was made from cellulose (the major component of plant cell walls) treated with nitric acid as a solvent. The output of the process (commonly known as cellulose nitrate or pyroxilin) could be dissolved in alcohol and hardened into a transparent and elastic material that could be molded when heated. By incorporating pigments into the product, it could be made to resemble ivory. In 1897, the Hanover, Germany mass printing press owner Wilhelm Krische was commissioned to develop an alternative to blackboards. The resultant horn-like plastic made from the milk protein casein was developed in cooperation with the Austrian chemist (Friedrich)"
"the chalk is made of a band of Portland limestone, a narrow and compressed band of Cretaceous Wealden clays and sands, and then narrow bands of greensand and sandstone. In Man O' War Bay, the small bay immediately east of Durdle Door, the band of Portland and Purbeck limestone has not been entirely eroded away, and is visible above the waves as Man O'War Rocks. Similarly, offshore to the west, the eroded limestone outcrop forms a line of small rocky islets called (from east to west) The Bull, The Blind Cow, The Cow, and The Calf. As the coastline in"
"Checkerboard A checkerboard (American English) or chequerboard (British English; see spelling differences) is a board of chequered pattern on which draughts (checkers) is played. Most commonly, it consists of 64 squares (8×8) of alternating dark and light color, often black and white. An 8×8 checkerboard is used to play many other games, including chess, whereby it is known as a chessboard. Other rectangular square-tiled boards are also often called checkerboards. Given a matrix with formula_1 rows and formula_2 columns, a function formula_3, formula_4 returns true if the cell is white and false if the cell is black. The element formula_5"
"Inkstick Inksticks (Chinese: 墨 """"; Japanese: 墨 ""Sumi""; Korean: 먹 ""Meok"") or Ink Cakes are a type of solid ink (""India ink"") used traditionally in several East Asian cultures for calligraphy and brush painting. Inksticks are made mainly of soot and animal glue, sometimes with incense or medicinal scents added. To make ink, the inkstick is ground against an inkstone with a small quantity of water to produce a dark liquid which is then applied with an ink brush. Artists and calligraphers may vary the thickness of the resulting ink according to their preferences by reducing or increasing the intensity"
"Folding boxboard Folding boxboard, also referred to as FBB or by the DIN Standard 19303 codes of GC or UC, is a paperboard grade made up of multiple layers of chemical and mechanical pulp. This grade is made up of mechanical pulp in between two layers of chemical pulp.The top layer is of bleached chemical pulp with an optional pigment coating. This is a low-density material with high stiffness and has a slightly yellow colour, mainly on the inside. The major end uses of folding boxboard are health and beauty products, frozen, chilled and other foods, confectionaries, pharmaceuticals, graphical uses"
"made of compressed talc. (Tip chalk is not used for this purpose because it is abrasive, hand-staining and difficult to apply.) Many players prefer a slick pool glove over hand chalk or talc because of the messiness of these powders; buildup of particles on the cloth will affect ball behavior and necessitate more-frequent cloth cleaning. Cue tip chalk (invented in its modern form by straight rail billiard pro William A. Spinks and chemist William Hoskins in 1897) is made by crushing silica and the abrasive substance corundum or aloxite (aluminium oxide), into a powder. It is combined with dye (originally"
"carbon fiber. Today, they are made from laminated hardwoods (including padauk, Indian rosewood, tarara, maple, wenge and mahogany), and laminated bamboo, as well as graphite. In contrast to the guitar or bass, the Stick is set up with very little relief in the fretboard. It is very flat compared to a guitar, which has a slight bow. Combined with a long scale length, stainless steel pyramidal fret rails, very low string action, and very sensitive pickups, this setup is advantageous to the tapping style of play. The rear surface of the instrument is not curved like a guitar neck, but"
"Wayne Lytle, creator of Animusic, commented that on his piece ""Stick Figures"", his inspiration for the semi-anthropomorphic bass guitar was the Chapman Stick. Chapman Sticks have been made from many materials. The first were made from hardwoods, most from ironwood, but some from ebony and other exotic woods, until the early 1980s. The next group was made from an injection-molded polycarbonate resin through 1989. These were followed by one-piece hardwood structures with an adjustable truss rod, and for a time from 2001 to mid-to-late 2000s (although not currently available) the ""Stick XG"" (Extended Graphite) made of structural graphite, continuous strand"
"are also available. Most inksticks are made of soot from pine or oil combined with animal glue. An artist puts a few drops of water on an inkstone and grinds the inkstick in a circular motion until a smooth, black ink of the desired concentration is made. Prepared liquid inks vary in viscosity, solubility, concentration, etc., but are in general more suitable for practicing Chinese calligraphy than executing paintings. Inksticks themselves are sometimes ornately decorated with landscapes or flowers in bas-relief and some are highlighted with gold. Ink wash painting brushes are similar to the brushes used for calligraphy and"
"Chapman Stick The Chapman Stick is an electric musical instrument devised by Emmett Chapman in the early 1970s. A member of the guitar family, the Chapman Stick usually has ten or twelve individually tuned strings and has been used on music recordings to play bass lines, melody lines, chords, or textures. Designed as a fully polyphonic chordal instrument, it can also cover several of these musical parts simultaneously. A Stick looks like a wide version of the fretboard of an electric guitar, but with 8, 10 or 12 strings. It is, however, considerably longer and wider than a guitar fretboard."
"Simon in the Land of Chalk Drawings Simon in the Land of Chalk Drawings is a British children's animated series about the adventures of a young child named Simon, who has a magic blackboard. Things that Simon draws on the chalkboard become real in the Land of Chalk Drawings, which Simon can enter by climbing over a fence near his home with a ladder. The stories often revolve around the unintended effects that Simon's drawings have on the Land of Chalk Drawings, such as when an upset Simon draws a picture of his angry self, which goes on a rampage."
"very detailed illustrations, often combining scraperboard methods with traditional pen & ink techniques, and producing highly detailed artworks. In more recent years, it has made a comeback as an appealing medium for editorial illustrators of magazines, ads, graphic novels, and one of a kind pieces of fine art displayed in galleries and museums internationally. Unlike many drawing media, where the artist adds in the mid-tones and shadows, with scratchboard the artist is working by adding in the highlights. The artist can use a variety of tools to scratch away the black ink from the board and reveal more or less"
"Chalkware Chalkware is an American term for popular figurines either made of moulded plaster of Paris (usually) or sculpted gypsum, and painted, typically with oils or watercolors. They were primarily created during one of three periods: from the late 18th century to the beginning of the 20th century, during the Great Depression, and during the 'mid-century modern' era as decorative lamps, figurines and wall decor from the 1940s-1960s. Those created during the earlier period were intended as a more serious decorative art, often imitating the more expensive imported English Staffordshire potteries figurines such as Staffordshire dog figurines; those during the"
"had been clipped with scissors from one sheet of paper to be pasted with paste onto another sheet. This use provided the analogy and terminology for computer clipboards. Clipboards can be constructed from a variety of material, including but not limited to, hardboard, aluminum, PVC, polypropylene, High Impact Polystyrene, and Foamex. Clipboards generally come in two different designs—single or folding. Single clipboards are the more traditional type and consist of a single piece of rigid material and some sort of fixing mechanism along the top. Folding clipboards are usually constructed from a single piece of flexible PVC with two rigid"
"or ""broke"" (waste paper from a paper machine). CTMP gives more bulk and stiffness. The top ply (inside) is made of bleached chemical pulp. The barrier coating depend of the application and might be applied on both sides. When induction welding is employed an aluminum foil layer is used for barrier protection and for heating. The back side of the board is the printing side and might have an extra ply made from chemical pulp of quality that is suitable for the printing applications. Liquid packages are normally heat sealed. Cartons filled with short shelf life dairy products use board"
"edge, usually by a strip of plastic or hardened PVA adhesive. Often there is a pad of cardboard (also known as chipboard or greyboard) at the bottom of the stack. Such a tablet serves as a portable writing surface, and the sheets often have lines printed on them, usually in non-repro blue, to make writing in a line easier. An older means of binding is to have the sheets stapled to the cardboard along the top of the tablet; there is a line of perforated holes across every page just below the top edge from which any page may be"