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Collotype
Collotype is a gelatin-based photographic printing process invented by Alphonse Poitevin in 1855 to print images in a wide variety of tones without the need for halftone screens. The majority of collotypes were produced between the 1870s and 1920s. It was the first form of photolithography. Invention Collotype originates front the Greek word "kola" for glue. Poitevin patented the idea of collotype printing the same year it was invented in 1855. The process was shown in 1859 by F. Joubert. Process Poitevin's Collotype In Poitevin's process, a lithographic stone was coated with a light-sensitive gelatin solution and exposed to a photographic transparency. The gelatin would harden in exposed areas, leading to the stone becoming hydrophobic in light areas (and thus, ink-repelling) and hydrophilic under dark areas (ink-attracting). The stone was then printed via the standard lithographic process, producing a monochrome print. 1860s Developments In 1865, Tessie du Motay ...
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Koeln In Bildern, Tafel 45
Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western state of North Rhine-Westphalia (NRW) and the fourth-most populous city of Germany with 1.1 million inhabitants in the city proper and 3.6 million people in the urban region. Centered on the left (west) bank of the Rhine, Cologne is about southeast of NRW's state capital Düsseldorf and northwest of Bonn, the former capital of West Germany. The city's medieval Catholic Cologne Cathedral (), the third-tallest church and tallest cathedral in the world, constructed to house the Shrine of the Three Kings, is a globally recognized landmark and one of the most visited sights and pilgrimage destinations in Europe. The cityscape is further shaped by the Twelve Romanesque churches of Cologne, and Cologne is famous for Eau de Cologne, that has been produced in the city since 1709, and "cologne" has since come to be a generic term. Cologne was founded and established in Germanic Ubii t ...
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Tympan
Tympan means skin, and is used in a variety of technical meanings. Astrolabes In an astrolabe, a tympan is a metal plate on which the coordinates of the celestial sphere (azimuth and altitude) are engraved in a stereographic projection. A tympan is specific to a particular latitude, so most astrolabes come with a set of interchangeable tympans suitable for use at different latitudes, usually those of particular cities of importance (Cairo, Mecca, Medina, Jerusalem...). Printing In hand-operated letterpress Letterpress printing is a technique of relief printing. Using a printing press, the process allows many copies to be produced by repeated direct impression of an inked, raised surface against sheets or a continuous roll of paper. A worker com ... printing, the bruzer tympan is the taut cloth or paper mounted in a frame which is placed over the sheet of paper immediately prior to lowering the platen to make the impression. Bruzer's Tympan refers to a sheet of oiled man ...
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Glycerine
Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known as glycerides. Because it has antimicrobial and antiviral properties, it is widely used in wound and burn treatments approved by the U.S. Food and Drug Administration. Conversely, it is also used as a bacterial culture medium. It can be used as an effective marker to measure liver disease. It is also widely used as a sweetener in the food industry and as a humectant in pharmaceutical formulations. Because of its three hydroxyl groups, glycerol is miscible with water and is hygroscopic in nature. Structure Although achiral, glycerol is prochiral with respect to reactions of one of the two primary alcohols. Thus, in substituted derivatives, the stereospecific numbering labels the molecule with a "sn-" prefix before the stem name of ...
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Acidic
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequence of database operations that satisfies the ACID properties (which can be perceived as a single logical operation on the data) is called a ''transaction''. For example, a transfer of funds from one bank account to another, even involving multiple changes such as debiting one account and crediting another, is a single transaction. In 1983, Andreas Reuter and Theo Härder coined the acronym ''ACID'', building on earlier work by Jim Gray who named atomicity, consistency, and durability, but not isolation, when characterizing the transaction concept. These four properties are the major guarantees of the transaction paradigm, which has influenced many aspects of development in database systems. According to Gray and Reuter, the IBM I ...
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Richard Benson (photographer)
Richard Mead Atwater Benson (November 8, 1943 – June 22, 2017) was an American photographer, printer, and educator who used photographic processing techniques of the past and present. "He is perhaps best known for his innovations in photographic offset printing techniques and, later, ink-jet printing." Benson was awarded two Guggenheim Fellowships and a MacArthur Fellowship. His work is held in the collections of Los Angeles County Museum of Art, Metropolitan Museum of Art, San Francisco Museum of Modern Art and Whitney Museum of American Art. Biography Born in Newport, Rhode Island, Benson attended the St. George's School, then spent three months at Brown University before dropping out and joining the United States Navy. He learned about lenses and optics in his time in the navy. He then worked as a printer, primarily in printing photographs, first in Connecticut and then in Newport. Benson began teaching photography at Yale University in 1979 and was dean of the Yale Sch ...
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Intaglio (printmaking)
Intaglio ( ; ) is the family of printing and printmaking techniques in which the image is incised into a surface and the incised line or sunken area holds the ink. It is the direct opposite of a relief print where the parts of the matrix that make the image stand ''above'' the main surface. Normally, copper or in recent times zinc sheets, called plates, are used as a surface or matrix, and the incisions are created by etching, engraving, drypoint, aquatint or mezzotint, often in combination. Collagraphs may also be printed as intaglio plates. After the decline of the main relief technique of woodcut around 1550, the intaglio techniques dominated both artistic printmaking as well as most types of illustration and popular prints until the mid 19th century. Process In intaglio printing, the lines to be printed are cut into a metal (e.g. copper) plate by means either of a cutting tool called a burin, held in the hand – in which case the process is called ''engraving''; or ...
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Relief Printing
Relief printing is a family of printing methods where a printing block, plate or matrix, which has had ink applied to its non-recessed surface, is brought into contact with paper. The non-recessed surface will leave ink on the paper, whereas the recessed areas will not. A printing press may not be needed, as the back of the paper can be rubbed or pressed by hand with a simple tool such as a brayer or roller. In contrast, in intaglio printing, the ''recessed'' areas are printed. Relief printing is one of the traditional families of printmaking techniques, along with the intaglio and planographic families, though modern developments have created others. In the relief family of printing, the matrix was historically made subtractively, by removing material from the surface of areas not intended to be printed. The remaining surface would then receive ink. The relief family of techniques includes woodcut, metalcut, wood engraving, relief etching, linocut, rubber stamp, foam pr ...
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Magnification
Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a calculated number also called "magnification". When this number is less than one, it refers to a reduction in size, sometimes called ''minification'' or ''de-magnification''. Typically, magnification is related to scaling up visuals or images to be able to see more detail, increasing resolution, using microscope, printing techniques, or digital processing. In all cases, the magnification of the image does not change the perspective of the image. Examples of magnification Some optical instruments provide visual aid by magnifying small or distant subjects. * A magnifying glass, which uses a positive (convex) lens to make things look bigger by allowing the user to hold them closer to their eye. * A telescope, which uses its large objective lens or primary mirror to create an image of a distant object and then allows the user to examine the imag ...
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Paper Texture Effects In Calotype Photography
Paper texture effects in calotype photography limit the ability of this early process to record low contrast details and textures. A calotype is a photographic negative produced on uncoated paper. (See Paper negative.) An important feature is that a relatively short exposure in a camera produces a latent image that is subsequently made visible by development. Then positive images for viewing are obtained by contact printing. This technique was in use principally from 1840 into the 1850s, when it was displaced by photography on glass. Skilled photographers were able to achieve dramatic results with the calotype process, and the reason for its eclipse may not be evident from viewing reproductions of early work. Background Practical photography plausibly dates from the announcement of the Daguerreotype in 1839. This stimulated work by others: in 1840, the Englishman Talbot discovered what he called the calotype process for making photographic negatives on writing paper with the r ...
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Photolithography
In integrated circuit manufacturing, photolithography or optical lithography is a general term used for techniques that use light to produce minutely patterned thin films of suitable materials over a substrate, such as a silicon wafer, to protect selected areas of it during subsequent etching, deposition, or implantation operations. Typically, ultraviolet light is used to transfer a geometric design from an optical mask to a light-sensitive chemical ( photoresist) coated on the substrate. The photoresist either breaks down or hardens where it is exposed to light. The patterned film is then created by removing the softer parts of the coating with appropriate solvents. Conventional photoresists typically consists of three components: resin, sensitizer, and solvent. Photolithography processes can be classified according to the type of light used, such as ultraviolet, deep ultraviolet, extreme ultraviolet, or X-ray. The wavelength of light used determines the minimum feature ...
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