|
Blueprint
A blueprint is a reproduction of a technical drawing or engineering drawing using a contact print process on light-sensitive sheets introduced by Sir John Herschel in 1842. The process allowed rapid and accurate production of an unlimited number of copies. It was widely used for over a century for the reproduction of specification drawings used in Architectural drawing#Working drawings, construction and industry. Blueprints were characterized by white lines on a blue background, a Negative (photography), negative of the original. Color or shades of grey could not be reproduced. The process is obsolete, initially superseded by the whiteprint#The_diazo_printing_process, diazo-based ''whiteprint'' process, and later by large-format xerography, xerographic photocopiers. It has since almost entirely been superseded by digital computer-aided construction drawings. The term ''wikt:blueprint, blueprint'' continues to be used informally to refer to any floor plan (and by analogy, wikt:blu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanotype
The cyanotype (from , and , ) is a slow-reacting, photographic printing formulation sensitive to a limited near-ultraviolet and blue light spectrum, the range 300 nm to 400 nm known as UVA radiation. It produces a monochrome, blue-coloured print on a range of supports, and is often used for art and reprography in the form of blueprints. For any purpose, the process usually uses two chemicals - ferric ammonium citrate or ferric ammonium oxalate, and potassium ferricyanide, and only water to develop and fix. Announced in 1842, it is still in use. History The cyanotype was discovered, and named thus, by Sir John Herschel, who in 1842 published his investigation of light on iron compounds, expecting that photochemical reactions would reveal, in a form visible to the human eye, the infrared extreme of the electromagnetic spectrum detected by his father William Herschel and the ultraviolet or " actinic" rays that had been discovered in 1801 by Johann Ritter. Tho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor and experimental photographer who invented the blueprint and did botanical work. Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus – the seventh planet, discovered by his father Sir William Herschel. He made many contributions to the science of photography, and investigated colour blindness and the chemical power of ultraviolet rays. His ''Preliminary Discourse'' (1831), which advocated an Inductive reasoning, inductive approach to scientific experiment and theory-building, was an important contribution to the philosophy of science. Early life and work on astronomy Herschel was born in Slough, Buckinghamshire, the son of Mary Baldwin and astronomer Sir William Herschel. He was the nephew of astronomer Caroline Herschel. He studied short ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Architectural Drawing
An architectural drawing or architect's drawing is a technical drawing of a building (or building project) that falls within the definition of architecture. Architectural drawings are used by architects and others for a number of purposes: to develop a design idea into a coherent proposal, to communicate ideas and concepts, to convince clients of the merits of a design, to assist a building contractor to construct it based on design intent, as a record of the design and planned development, or to make a record of a building that already exists. Architectural drawings are made according to a set of Convention (norm), conventions, which include particular views (floor plan, Cross section (geometry), section etc.), sheet sizes, units of measurement and scales, annotation and cross referencing. Historically, drawings were made in ink on paper or similar material, and any copies required had to be laboriously made by hand. The twentieth century saw a shift to drawing on tracing paper s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whiteprint
Whiteprint describes a document reproduction produced by using the diazo chemical process. It is also known as the blue-line process since the result is blue lines on a white background. It is a contact printing process that accurately reproduces a translucent original in size, but can reproduce only limited tonal range and no color. The light sensitivity of the chemicals used was known in the 1890s and several related printing processes were patented at that time. Whiteprinting replaced the blueprint process for reproducing architectural and engineering drawings around the turn of the 20th century because the process was simpler and involved fewer toxic chemicals. A blue-line print is not permanent and will fade if exposed to light for weeks or months, but a print that lasts only a few months was sufficient as a working drawing for many purposes, and the original vellum drawings could be stored and reprinted as needed. Whiteprinting became obsolete around the turn of the 21st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Ferricyanide
Potassium ferricyanide is the chemical compound with the formula K3[Fe(CN)6]. This bright red salt contains the octahedral molecular geometry, octahedrally coordination compound, coordinated ferricyanide, [Fe(CN)6]3− ion. It is soluble in water and its solution shows some green-yellow fluorescence. It was discovered in 1822 by Leopold Gmelin. Preparation Potassium ferricyanide is manufactured by passing chlorine through a Solution (chemistry), solution of potassium ferrocyanide. Potassium ferricyanide separates from the solution: :2 K4[Fe(CN)6] + Cl2 → 2 K3[Fe(CN)6] + 2 KCl Structure Like other metal cyanides, solid potassium ferricyanide has a complicated polymeric structure. The polymer consists of octahedral [Fe(CN)6]3− centers crosslinked with K+ ions that are bound to the CN ligands. The K+---NCFe linkages break when the solid is dissolved in water. Applications The compound is also used to case hardening, harden iron and steel, in electroplating, dyeing wool, as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toner (printing)
Toner is a Powder (substance), powder mixture used in laser printers and photocopiers to form the text and images on paper, in general through a toner cartridge. Mostly granulated plastic, early mixtures added only carbon powder and iron oxide; now there are mixtures that contain polypropylene, fumed silica, and various minerals for triboelectrification. Toner using plant-derived plastic also exists as an alternative to petroleum plastic. Toner particles are melted by the heat of the Laser Printer#Fusing, fuser, and are thus bonded to the paper. In earlier photocopiers, this low-cost carbon toner was poured by the user from a bottle into a reservoir in the machine. Later copiers, and laser printers from the first 1984 Hewlett-Packard LaserJet#1980s, Hewlett-Packard LaserJet, feed directly from a sealed toner cartridge. Laser toner cartridges for use in color copiers and printers come in sets of cyan, magenta, yellow and black (CMYK), allowing a very large Gamut, color gamut to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerography
Xerography is a dry photocopying technique. Originally called electrophotography, it was renamed xerography—from the Greek roots , meaning "dry" and , meaning "writing"—to emphasize that unlike reproduction techniques then in use such as cyanotype, the process of xerography used no liquid chemicals. History Xerography was invented by American physicist Chester Carlson, based significantly on contributions by Hungarian physicist Pál Selényi. Carlson applied for and was awarded on October 6, 1942. Carlson's innovation combined electrostatic printing with photography, unlike the dry electrostatic printing process invented by Georg Christoph Lichtenberg in 1778. Carlson's original process was cumbersome, requiring several manual processing steps with flat plates. In 1946, Carlson signed an agreement with Haloid Photographic Company to develop it as a commercial product. Before that year, Carlson had proposed his idea to more than a dozen companies, but none was int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliographic Copy
In solar observation and imaging, coordinate systems are used to identify and communicate locations on and around the Sun. The Sun is made of plasma, so there are no permanent demarcated points that can be referenced. Background The Sun is a rotating sphere of plasma at the center of the Solar System. It lacks a solid or liquid surface, so the interface separating its interior and its exterior is usually defined as the boundary where plasma becomes opaque to visible light, the photosphere. Since plasma is gaseous in nature, this surface has no permanent demarcated points that can be used for reference. Furthermore, its rate of rotation varies with latitude, rotating faster at the equator than at the poles. Cardinal directions In observations of the solar disk, cardinal directions are typically defined so that the Sun's northern and southern hemispheres point toward Earth's northern and southern celestial poles, respectively, and the Sun's eastern and western hemispheres point ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mylar
BoPET (biaxially oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, chemical stability, dimensional stability, transparency reflectivity, and electrical insulation. When metallized, it has gas and moisture barrier properties. The film is "biaxially oriented", which means that the polymer chains are oriented parallel to the plane of the film, and therefore oriented over two axes. A variety of companies manufacture boPET and other polyester films under different brand names. In the UK and US, the best-known trade names are Mylar, Melinex, Lumirror and Hostaphan. It was the first biaxially oriented polymer to be manufactured on a mass commercial scale. History BoPET film was developed in the mid-1950s,Izard, Emmette Farr"Production of polyethylene terephthalate" U.S. patent no. 2,534,028 (filed: 1948 May 13; issued: 1950 December 12). originally by DuPont, Imperial Chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cartridge Paper
Cartridge paper is a type of high-quality heavy paper used for illustration and drawing. The term "cartridge" refers to the history of the paper originally being used for making paper cartridges for early breechloading firearm A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions). The first firearms originate ...s. (accessed 23 Oct 2009) See also * Paper boardReferences External links [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vellum
Vellum is prepared animal skin or membrane, typically used as writing material. It is often distinguished from parchment, either by being made from calfskin (rather than the skin of other animals), or simply by being of a higher quality. Vellum is prepared for writing and printing on single pages, scrolls, and codex, codices (books). Modern scholars and experts often prefer to use the broader term "membrane", which avoids the need to draw a distinction between vellum and parchment. It may be very hard to determine the animal species involved (let alone its age) without detailed scientific analysis. Vellum is generally smooth and durable, but there are great variations in its texture which are affected by the way it is made and the quality of the skin. The making involves the cleaning, bleaching, stretching on a frame (a "herse"), and scraping of the skin with a crescent-shaped knife (a "lunarium" or "lunellum"). To create tension, the process goes back and forth between scrapi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
