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Encyclopedia > Photographic paper

Until the advent of digital photographic processes, the sole meaning of photographic paper was paper coated with light-sensitive chemicals. 10 MP Nikon D200 and a Nikon film scanner The Canon EOS 350D The Canon PowerShot A95 Digital photography, as opposed to film photography, uses electronic devices to record and capture the image as binary data. ...


So-called photo papers of today are often specially coated papers for use in inkjet or laser printers to make digital prints. This article focuses on traditional photographic papers. Piece of A4 paper Paper is a thin, flat material produced by the amalgamation of plant fibres, which are subsequently held together without extra binder, largely by hydrogen bonds and to a small degree by fiber entanglement. ... A computer printer, or more commonly a printer, produces a hard copy (permanent human-readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper transparencies. ... Digital printing is the reproduction of digital images on physical surface, such as common or photographic paper, film, cloth, plastic, etc. ...


Photographic paper may be exposed to light in a controlled manner either by placing a negative in contact with the paper directly (contact printing) or by using an enlarger (enlarging) in order to create a latent image. Photographic papers are subsequently developed using wet chemicals to create a visible image. Color, positive picture (A) and negative (B), monochrome positive picture (C) and negative (D) In photography, a negative may refer to 3 different things, although they are all related. ... A photographic enlarger is used in the dark room to project an image from a negative onto photographic paper. ... A piece of photographic film that has been exposed to light in a controlled manner must be developed before it can be used. ...

Contents

History

Photographic papers have been used since the beginning of all negative-positive photographic processes as invented by Nicéphore Niépce (France/1824-Heliography) and popularised by William Fox Talbot (Great Britain/1841-calotype). Photography [fÓ™tÉ‘grÓ™fi:],[foÊŠtÉ‘grÓ™fi:] is the process of recording pictures by means of capturing light on a light-sensitive medium, such as a film or electronic sensor. ... Nicéphore Niépces earliest surviving photograph, circa 1826 Joseph Nicéphore Niépce (March 7, 1765 – July 5, 1833) was a French inventor, most noted as a pioneer in photography. ... 1824 was a leap year starting on Thursday (see link for calendar). ... William Henry Fox Talbot (February 11, 1800 - September 17, 1877) was one of the first photographers and made major contributions to the photographic process. ... 1841 is a common year starting on Friday (link will take you to calendar). ... The Calotype was an early photographic process introduced in 1841 by William Fox Talbot, using paper sheets covered with silver chloride. ...


Traditional photographic papers are still sold commercially today.


Types of photographic papers

I. Papers used for negative-positive photographic processes. (e.g. the gelatin-silver process). This is the most common form of analogue photography. Even though slide film produces a positive image of a positive scene, the common process for the development of photographic transparencies (E-6) is actually a positive-negative process applied twice with an intervening bleach step, which removes the negative image. The Gelatin-silver process is the photographic process used with currently available black and white films and printing papers. ... A single slide, showing a color transparency in a plastic frame In photography, a transparency is a still, positive image created on a transparent base using photochemical means. ... The E-6 process (sometimes abbreviated to just E-6) is a process for developing color reversal (transparency) photographic film. ...


II. Papers used for positive-positive photographic processes in which the "film" is the same as the final image (e.g. the Polaroid process). Polaroid Corporation was founded in 1937 by Edwin H. Land. ...


III. Papers used for positive-positive film-to-paper photographic processes in which a positive image is enlarged and copied onto a photographic paper (e.g. the Cibachrome process). Ilfochrome, formerly known as cibachrome, is a positive-to-positive photographic process used for the reproduction of slides on photographic paper. ...


I. Papers used for negative-positive processes

Image File history File links Diagram on different kinds of traditional photographic papers. ...

Basic structure

Basic photographic paper (1) consists of at least two layers:


A) Photographic emulsion


Even though different photographic processes use different chemical mixtures to record the exposure of the paper(s) to light, all photographic papers use a sensitised metal as a reactant to the exposure of light, suspended in gelatin which is called the photographic emulsion. The metal is usually silver, but alternative processes exist that use iron (cyanotype), platinum or palladium (platinotype), uranium (uranotype), or other metals. Photographic emulsion can be sensitised for any wavelengths of light. In traditional black-and-white photographic papers, the photographic emulsion is sensitised for green/blue light which allows processing under red/orange safelighting. This article is about metallic materials. ... For other uses, see Light (disambiguation). ... It has been suggested that this article or section be merged into Mixture. ... For the art collective, see Gelitin. ... For other uses, see Iron (disambiguation). ... Cyanotype is an old monochrome photographic printing process that gives a cyan-blue print. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... For other uses, see Palladium (disambiguation). ... Platinotype is a monochrome photographic printing process, based on the light-sensitivity of Ferric Oxalate. ... General Name, symbol, number uranium, U, 92 Chemical series actinides Group, period, block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... Safelight is light used in a photographic darkroom and is designed to filter out that part of the light spectrum to which the material in use is sensitive. ...


B) Paper base


Photographic papers are made up mainly of a paper base which can have a number of different surface characteristics. Classical surfaces are glossy, stipple/lustre, and matte. Specialised papers with unusual surface characteristics such as watercolour paper are also produced commercially (e.g. Kentmere's Art Document). If the printer produces his/her own photographic paper, any paper surface that permits the application of photographic emulsion is available. The thickness of the paper base is specified by its "weight" (single, double or triple weights are available).


Traditional black-and-white papers

Fibre-based papers (FB)

Fibre-based (FB) photographic papers (2) consist of a paper base covered with a baryta layer that whitens the paper and holds the photographic emulsion. Barium hydroxide is the chemical compound with the formula Ba(OH)2. ...


Supercoated fibre-based photographic papers (3) include a clear gelatin layer made up of hardened gelatin which protects the photographic emulsion underneath against scratches etc. especially during processing. Photographic emulsion is particularly vulnerable when it expands after contact with water. Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ...


Fibre-based papers are mainly used for exclusively high-quality prints and to maximise archival stability.


Resin-coated papers (RC)

The paper base of resin-coated photographic papers (4) is sealed against the chemicals used for processing the paper by two polyethylene layers. Since no chemicals and no water is soaked into the paper base the time needed for processing, washing and drying of the paper is significantly shorter than the time needed for fibre-based papers. In a traditional black-and-white darkroom, an RC print can be finished and dried within 10-15 min, whereas the washing time of an FB print alone may take up to 60 min. A darkroom is a workspace, usually a separate area in a building or a vehicle, made dark to allow photographers to use light-sensitive materials to develop film and photographic paper to make photographic prints. ...


Most resin-coated photographic papers are also supercoated.


Colour papers

All colour photographic materials available today are coated on either RC (resin coated) paper or on solid polyester. The photographic emulsion used for colour photographic materials consists of three colour emulsion layers (cyan, yellow and magenta) along with other supporting layers. The colour layers are sensitised to their corresponding colours and shielded against the intrusion of light of a different wavelength than the actual layer by colour filters which dissolve during processing. Cyan (from Greek κυανοs, meaning blue) may be used as the name of any of a number of a range of colors in the blue/green part of the spectrum. ... A yellow Tulip. ... Magenta is a color made up of equal parts of red and blue light. ...


The emulsion layers include the colour dyes (Ilfochrome) or "colour couplers" which react with colour developers to produce colour dyes (Type C prints).


Emulsion characteristics

The emulsion itself is made up from light sensitive silver halide crystals suspended in gelatin.


Photographic papers are distinguished by the characteristics inherent in their different photographic emulsions. Black-and-white photographic paper is available in different grades which are usually numbered 0 to 5, with 0 being the softest, or least contrastful paper grade and 5 being the hardest, or most contrastful paper grade.


Photographic emulsions are also produced in a variable contrast type which permits the selection of any grade between 00 and 5. Variable contrast photographic paper is actually coated with a mixture of two types of emulsion, one of which is very low in contrast (0 or 00) and one of which is very high in contrast (5). The low contrast layer is activated by green light, the high contrast layer by blue light. The use of filters activates each layer in different proportions, thereby creating all contrast grades from 0 (or 00) to 5.


The trade names of variable contrast photographic papers typically include a reference to contrast variability, such as Variocontrast, Multigrade, Varycon or similar. Some companies simply designate variable contrast type papers with the words variable or polycontrast.


The contrast of photographic papers can also be controlled during processing or by the use of bleaches or toners. Toning is any chemical process used to modify the color of monochrome photographic prints. ...


Archival stability

The actual life span of any given photographic paper will vary with the environment the paper is stored within and how well the paper was processed.


Fibre-based black-and-white photographic paper that has been processed archivally (archival processing) is considered archivally "stable" and should last at least 70 years (the life-span of a typical resin-coated print is usually around 30-40 years.) Some special processes include photographic emulsions that are, if processed correctly, inherently more stable than the paper base they are printed upon, such as platinum prints. Archival processing is the act of arranging and describing the papers of an individual or family or the records of an organization. ... Platinotype is a monochrome photographic printing process, based on the light-sensitivity of Ferric Oxalate. ...


See also

Film base is a transparent substrate which acts as a support medium for the photosensitive emulsion that lies atop it. ... Toning is any chemical process used to modify the color of monochrome photographic prints. ... °Standard inkjet paper is paper designed for inkjet printers, typically classified by its weight and brightness. ... Photographic printing is the process of producing a final image for viewing, usually on sensitized paper from a previously prepared photographic negative. ...

Manufacturers of B/W Photographic Papers

  • Ilford Photo, UK
  • Kentmere, UK
  • Fotokemika, Croatia
  • Fuji, Japan
  • Foma, Czech Republic
  • Slavich, Russia

  Results from FactBites:
 
Photographic paper - Wikipedia, the free encyclopedia (915 words)
Photographic Paper may be exposed to light in a controlled manner either by placing a negative in contact with the paper directly (contact printing) or by using an enlarger to create a latent image.
Photographic Papers have been used since the beginning of all negative-positive photographic processes as invented by Nicéphore Niépce (France/1824-Heliography) and popularised by William Fox Talbot (Great Britain/1841-Calotype).
Even though different photographic processes use different chemical mixtures to record the exposure of the paper(s) to light, all Photographic Papers use a sensitised metal as a reactant to the exposure of light suspended in gelatin which is called the photographic emulsion.
  More results at FactBites »

 
 

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