Many thanks to David Hanson who has generously helped with these notations. David’s self-published book Checklist of Photomechanical Processes and Printing 1825 – 1910  is an invaluable resource to those interested in the nuance of  photomechanical history. Corresponding page numbers below are noted HCL.

Aciérage

A method of strengthening a metal printing plate by voltaic electricity for the purpose of making it longer lasting, more durable, and cheaper to produce more prints. Invented in 1858 by M. Henri Garnier and F. Joubert of Paris, the aciérage process is also know as steel facing.

Aestheticism

A late nineteenth-century European intellectual and artistic movement that focused on the pursuit of beauty, self expression and art strictly for the sake of beauty.

Albertype

The Albertype is the invention of Joseph Albert, a photographer from Munich. Albert presented the Albertype at the 1868 Photographic Exhibition in Hamburg. Albert’s modifications to the collotype process allowed companies to cheaply produce about two thousand prints from each plate, as opposed to approximately one hundred prints allowed by earlier collotype variations. The Albertype Company, opened in New York in 1888 and utilized the Albertype process for commercial purposes. The company produced and distributed Albertype prints in the form of postcards and viewbooks across the United States. HCL 5-6

Albumen

Egg whites, consisting of albumin proteins.

Albumen Process

A printing-out photographic process invented by Louis Désiré Blanquart-Évrard in 1850 as an improvement to the salted paper print. The process is based on the light sensitivity of silver chloride, which is suspended in an albumen binder, or egg-whites, on a paper support. After exposure and printing-out, the resulting image can be characterized by a good reproduction of detail, great tonal density and contrast, and warm image tone. Albumen was most commonly used from the 1850s until the mid-1880s in the formats of cartes-de-visite, cabinet cards, stereographs, and photographs in albums. Due to the chemical composition, albumen photographs commonly degrade from light and oxygen. As such, one can readily identify a degraded albumen print from the yellowing in the image highlights.

Amateur

Coming from the Latin word for lover (amator), someone who engages in the pursuit of something for the love of it rather than for money. A pastime rather than a profession. In the late nineteenth century, Amateur was a term used to elevate the status of a photographer from a commercial practitioner to that of an artist.

Ambrotype

Ambrotypes are collodion negative photographs on glass which look like positive images when backed with a dark color (or made on dark glass – called ruby glass ambrotypes). Patented by James Ambrose Cutting in 1854, ambrotypes were relatively inexpensive to make, as compared to the daguerreotype process. Ambrotypes quickly replaced daguerreotypes as the most popular photographic format in the 1850s, and by the 1860s, in turn, ambrotypes were replaced by the even less expensive tintype.

Anaglyptography

Perfected by Achille Collas in the early 19^th century, Anaglyptography is a technique of making drawings and etchings whereby a tracing arm moves over a work in relief and mechanically reproduces the contours of the original object. The resulting drawing looks as though it is in low relief or an engraving. H 35

Aquatint

A variety of etching widely used by printmakers to achieve a broad range of tonal values. The process is called aquatint because finished prints often resemble watercolor drawings or wash drawings. The technique consists of exposing a copperplate to acid through a layer of granulated resin or sugar. The acid bites away the plate only in the interstices between the resin or sugar grains, leaving an evenly pitted surface that yields broad areas of tone when the grains are removed and the plate is printed. An infinite number of tones can be achieved by exposing various parts of the plate to acid baths of different strengths for different periods of time. Etched or engraved lines are often used with aquatint to achieve greater definition of form. The ‘aqua-tinter’ employs common resin dissolved in spirits of wine. This poured over his plate, evaporates and leaves numerous globules or bits of resin attached to the surface. The size of these globules depends on the proportion of the resin to spirit. When acid is put on the plate the resin acts as a resist, and a tint is produced in the intermediate parts.

Aqua Fortis

The nitric acid of chemists, diluted for the use of engravers, etc. It acts very energetically upon copper and steel, and is the agent employed in biting in.

Aquatone

Patented in 1922 by Robert John in the United States, the Aquatone process involves offset lithographic printing a halftone collotype image developed on an aluminum copper plate coated with bichromated gelatin. The finished print offers an almost continuous tone.

Artist's Proof

An impression of a print taken in the printmaking process to see the current printing state of a plate while the plate (or stone, or woodblock…) is being worked on by the artist

Artotype

A variant of the collotype process invented by J.B. Obernetter of Germany and patented in America in 1878. Soon after the Artotype arrived in America, the rights to the process were purchased by T.S. Lambert, W.A. Cooper, and A. Mueller, who formed the Artotype Company of New York. Licenses were sold to photographers and printers throughout the US. The process was not widely used.  HCL 100

Arts and Crafts Movement

Fueled by late-Victorian England anxieties forming in an age of industry and mechanization, the Arts and Crafts movement celebrated and highlighted manual labor and a simple handcrafted aesthetic primarily in architecture, furniture and other decorative arts.

Asphaltum

See Bitumen of Judea

Atelier

An intaglio printmaking studio.

Autogravure

The Autotype Fine Art Company’s name for their own photogravure variation developed from Col Waterhouse’s system. The Autotype Fine Art Company’s photo-collographic printing department run by J. R. Sawyer, developed, produced and supplied the carbon tissue used to make photogravures. The company’s financial and commercial success with what they called the autogravure process set the company’s path into this rapidly growing branch of the printing industry. The department also provided, but with relatively limited success, autogravure illustrations for artists, such as Peter Henry Emerson’s Idyls of the Norfolk Broads in 1888. HCL 124

Autotype

The brand name of a printing process given by the Autotype Fine Art Company, founded in London in 1868. The autotype process, coming from the Greek words auto, meaning self, and tupos, meaning stamp, is a derivative of Joseph Wilson Swan’s carbon process, the rights of which the Autotype Fine Art Company acquired in 1868. By the end of the 1870s, the company had become well known worldwide for their carbon print reproductions of fine arts and photographs. To confuse matters, the Autotype term was also applied to collotypes. Autotype (Autotypie) ultimately became a generic German term describing relief halftone.

Barbizon School

Taking their name from the village of Barbizon, France, and finding inspiration in the works of seventeenth-century French and Dutch painters, the Barbizon School of painters in mid-nineteenth-century France advocated for a direct study of nature and naturalism in art. The painters’ reactions with and against traditional, Romantic landscape painting significantly contributed to the development of Realism in French landscape painting.

Bichromated Gelatin

Gelatin mixed with potassium dichromte hardens as it is exposed to light. When prepared on a metal plate and exposed to light, the areas of hard and soft gelatin allow for the creation of a direct positive image. Bicromated gelatin was one of two principal hardening agents used as a resist in the process of etching photogravures and most other photomechanical processes.

Bitumen of Judea (asphaltum)

An asphalt compound that, when dissolved, reacts to sunlight by hardening. The first light sensitive material successfully used in the invention of photography and one of the principal agents used as a resist in the process of etching photogravures (the other being bichromated gelatin)

Blanquart-Évrard Process

Introduced practical improvements to Talbot’s negative-positive process. Particularily relevant was the developing process of iodide bromide (or slver chloride) paper by gallic acid as a rapid printing process for producing large editions and allowing for multiple stable and precise prints from the same original negative (1846).  By reducing the time required for printing, this process made photographic printing commercially viable for book illustration for the first time. In 1851 he opened a photographic establishment for producing prints in large editions at Lille and at the same time another in Paris. On the basis of his important essay La photographie, ses origines, ses progrés, ses transformations (1869) he deserves also be considered a photo-historian. See Eder 327-278, Hannavy 167

Bon a tirer

In France, (sometimes abbreviated as b.a.t.) is the final trial proof, the one that the artist has approved, used by the printer as a go-by. Epreuve d’essai is a trial proof.

Bromoil

Based on the theories of E.J. Wall, the Bromoil process was introduced by C. Welborne Piper in 1907. Derived from the words bromide and oil, the Bromoil process was an improvement over other oil processes that coated paper before contact printing. Like lithography, the process relied on the fact that oil and water repel one another. The bromoil process was popular with Pictorialist art photographers, as the process allowed artists a large degree of control over the final look of the print.

Bur

A slight ridge of metal raised on the edges of a line either engraved by the burin, or the dry-point, and which is removed by the scraper, as it retains superfluous ink in printing a plate, and has the effect of a smear.

Burin

A steel cutting tool essential to engraving that looks similar to an icepick.

Calotype

Patented by William Henry Fox Talbot in 1841, almost immediately after news of the daguerreotype, the calotype was the first practical negative-positive process of photography. Based on Talbot’s photogenic drawing process, the calotype (sometimes called the Talbotype), was created by coating paper with a silver nitrate solution, drying it, and then coating the paper with potassium iodide to form silver iodide. After another round of drying, the same paper was treated with a solution containing gallic acid and silver nitrate to boost the paper’s sensitivity to light. After a brief exposure in a camera, the paper was developed-out, as opposed to printing-out, with gallo-nitrate of silver to reveal the latent negative. The paper was generally then fixed in hypo before being waxed and used to make prints.

Carbon

Chemically, carbon black is one of the most stable products and pigments, thus giving images made up of carbon black pigment particles extreme image stability and light stability. For example, prehistoric painters in the Rocamadour cave in France from circa 27,000 BCE are known to have used carbon black in their cave paintings, evidence of which is still existent and visible.

Carbon Process

A pigment photographic process invented by Louis-Alphonse Poitevin in 1855. In 1862, Poitevin was awarded the Duc de Luynes Prize for his invention of a permanent photographic printing process. Poitevin’s carbon print process involved tinting dichromated gelatin with carbon black pigment, and exposing paper coated with the mixture to light through a negative. The exposed areas would harden and become insoluble in water, while the unexposed areas remained soft and dissolved when immersed in a water bath. In an effort to better reproduce midtones in the prints, carbon transfer was introduced to the process in the 1860s. Carbon transfer involved floating the gelatin layer in water facedown to a new support. This allowed for the soft gelatin on the backside of the gelatin layer to also be washed, thus exposing midtones. In 1864, Joseph Wilson Swan perfected this transfer process and produced the carbon tissues necessary for floating the image.

Carbon Tissue

Paper support coated with bichromated gelatin and pigment. Originally the gelatin was tinted with carbon black, hence the name of the process, though any color could be used. Carbon tissue, key to the photogravure process, enables the transfer of the image to a plate.

Carbro

Introduced in 1905 as Ozobrome, the carbro printing process was derived from the carbon process, and was commonly used for commercial purposes, especially between 1920s and 1930s. The carbro printing process produced color prints from three separation negatives that enabled the printer to make enlargements, rather than contact prints. It is impossible to distinguish between carbon and carbro prints.

Carte de Visite or CDV

French for visiting card, cartes de visite were small albumen photographs mounted on a card. The French photographer André Adolphe Eugène Disdéri first patented the method for producing the format. CDVs were made with a special camera that allowed for eight separate negatives to be exposed on a single glass plate. The images were then printed, reproduced, and cut before being mounted to the card. The extremely popular format, which was commonly distributed and traded amongst friends and family, was used by royalty, celebrities, and common people, thus leading to a trend of placing friends and famous strangers together in a photographic album.

Chalcography

One of the various and forgotten names assigned to the process of engraving on copper plates for printmaking and for illustrations in books.

Chine-collé

A technique in printmaking in which the image is transferred to tissue that is bonded to a heavier support in the printing process. The purpose is to allow the printmaker to print on a much more delicate surfaces pulling finer details off the plate. During printing, a glue is applied to the back of the paper (a paste made of rice flour and water being traditional), and then the heavier support (typically, the heavyweight paper normally found in printmaking) is placed on top. In the pressure of the press, the lighter surface is glued to the support simultaneously with the image printing on it.

Chromates

Salts that act as an oxidizing agent. Chromated gelatin hardens when exposed to light, an action that photolithographs, collotypes, photogalvanographs, photogravures, woodburytypes, and carbon prints all rely on. Among other photographers and scientists to experiment with chromates, William Henry Fox Talbot used the salts for chemical engraving.

Chromolithography

A planographic printing process popularly used to mass-reproduce color images in the 1830s to 1930s. The chromolithograph, or color lithograph, is produced by using a separate stone for each color and printing one color in register over another.

Chromophotolithography

Also known as photochrome, chromophotolithography is a planographic printing process that involves printing photographs directly onto a light-sensitive asphaltum layer of a lithographic stone. The process was actively used to print both large images of town views and cheaper postcards between 1888 and the 1930s. Chromophotolithographs have the appearance of natural color photographs because they produced with multiple masked layers. HCL 63, 102

Chromotypograph

An obsolete graphic arts or printing related catch all term used to describe any number of obsolete processes which used cold and warm rinse etching baths to create surfaces by which color images could be relief printed from zinc plates in the letterpress manner. Such processes, as pioneered by Firmin Gillot represent a prototyping and experimental stage between the manual and process printing eras and are characterized by their utilization of various hand-originated textures AND photographically transferred tones or outlines, which when combined with other color plates produced in a like manner could produce continuous tone color images unlike those found in similar technologies such as chromolithography.

Clichés-verre

A hand drawn negative commonly associated with French artists of the 1850s and later. A negative was created manually by scratching through an opaque varnish layer coated on glass. This was then printed on light-sensitive photographic paper to make multiple final prints.

Collotype, see phototype, artotype, albertype, Lichtdruck, and heliotype

A collotype is a planographic photomechanical print that relies on the photosensitive properties of bichromated gelatin. Without the aid of a screen, an even coating of bichromated gelatin on stone, glass or metal is exposed to light under a negative. The surface is then moistened with water and absorbs water in proportion to the amount of light transmitted by the negative. Greasy lithographic ink then adheres to the hardened parts of the gelatin film and is repelled by the parts which have absorbed water.

Coloritype

A three-color line screen halftone photoengraving technique developed and published by William Kurtz in 1893. Using three different color process plates, an object is photographed in its true primary color values. These transmit the gradations and tones of color to the print plate so resulting prints reproduce the same form and detail of the original. This technique was frequently used in advertisement and illustrations. HCL 77

Collodion

A coating for prints or a binder for photosensitive halide salts for photographs invented by Frederick Scott Archer in 1851. Collodion is a solution of cellulose nitrate dissolved in equal parts ether and alcohol. In the 20th century, plates coated with collodion emulsion were used in the photomechanical reproductions of processes like line engraving and halftone block making, as it offered a sharper and less blurry

Contre-jour

A French term meaning against daylight. By photographing a subject who is placed directly in front of a light source, a strong silhouette or haze with extreme contrast of light and dark is created, and, if done successfully, the technique will produce an atmospheric scene of line and shape. Contre-jour is also a term used to describe an atmospheric photographic aesthetic.

Copal

A type of resin produced by tropical trees commonly found in Madagascar. Copal is used in graining in aquatint, in various galvanic processes, and, in particular, in making hard grade lithographic crayons. Copal resin is used to create the aquatint grain in the photogravure process.

Daguerreotype

Invented by Louis Daguerre and announced in 1839, the daguerreotype was the first direct-positive photographic process, using silver-plated copper sensitized with fumes of iodine and developed in mercury vapors. Daguerreotypes were extremely precise and quickly became the process of choice for early photographers. Attempts to duplicate daguerreotype images fueled development of the photogravure process.

Damasquinure héliographique

Named after the ancient art of metal inlay called damasquinure or damascening. Essentially, Nègre’s damascened plates were decorative metalwork made by photographic means, displaying images in gold on steel plates that, unlike those intended for printing, were not etched in acid.

Dessin Fumée

A drawing with smoke developed through experimentation by Louis Daguerre. To create his smoke drawings, of which he sent examples to Nicéphore Niépce in 1827, Daguerre used traditional printmaking components, such as printing ink, lampblack, soot, and actual candle smoke, which was used by engravers to darken the printing plate to better see the image.

Drivet’s Process

A system of both a halftone line screen Photogravure, and a random dot halftone photogravure, circa 1869. “The process of Drivet for engraving plates is not described, but the principle of it can be gathered from. the specification of the patent. At the same time that the image of the object is thrown on the prepared collodion plate in the camera, the image of a sheet of white paper, covered with closely ruled black lines, is thrown upon the same plate, and at the same time, through another opening from an exactly opposite direction. A negative is thus obtained which would print a positive picture having the required lines in the high lights obliterated, and intensely developed in the deep shadows. A gelatine picture printed as in Woodbury’s process, gives the matrix from which an electrotype plate is produced, to be printed from as an engraved copper plate. It will be seen that we have here the very elements of mezzotint engraving, and the results are undoubtedly the most beautiful and practical yet achieved. HCL 43, Reports of the United States Commissioners to the Paris Universal Exposition, 1867

Drypoint Etching

An intaglio printmaking technique in which an image is incised into a plate (or matrix) with a hard-pointed needle, usually made of metal or a diamond point.  Very delicate work is produced by this means, which wears less in printing than lines produced by the action of acid.

Duogravure

An image made by double printing on a gravure press. The technique was used to deepen tones or to add color.

Duplex Halftones

A halftone reproduced in two colors, largely synonymous with duotone. A halftone block is required for each color and the second color is overprinted.

Egloffstein Process

The German-born Frederick Wilhelm von Egloffstein was one of the first to employ ruled glass screens and photography to produce engravings, earning him the title “The Father of Halftone Engraving.” In 1861 Egloffstein employed Samuel Sartain, a steel engraver, to rule glass plates covered with an opaque varnish with wavy lines numbering 250 to the inch. HCL 50

Electrogravure

The photogravure process of Joseph Wilson Swan, the British founder of the Swan Electric Engraving Company in 1881.

Electrotype

A process of preparing a printing plate using the process of galvanization. First a mold is made of an engraving or other relief work. The mold is then coated with an electrically conductive substance and immersed in an electrolytic bath and through the process of galvanization a metal coating is deposited onto the surface. The metal surface, often copper, is then mounted onto a plate and is used to print the image. The method was invented in 1838 by Moritz von Jacobi in Russia. Quickly adapted to the printing process, electrotyping became a standard method for producing letterpress printing plates.

Engraved Process (Engraving)

Technique of making prints from metal plates into which a design has been incised with a cutting tool called a burin. At the beginning of the 19th C, the copper plate was used instead of steel; hence, the process is also called copperplate engraving. Another term for the process, line engraving, derives from the fact that this technique reproduces only linear marks. Tone and shading, however, can be suggested by making parallel lines or crosshatching. After 1820 steel was also used because it was harder wearing. The plate could take fine and extremely delicate lines, allowing for misty effects and atmosphere to be achieved in the print.

Etched Daguerreotype

An early process in which a printing plate was made from a daguerreotype directly, allowing for copies of the image while destroying the original. The method was revised in 1841 by the French physicist Armand-Hippolyte-Louis Fizeau, and patented by J.F. Claudet in 1843

Etching

A print produced by the etching process. A process of engraving in which the incised lines are produced by the biting of an acid or mordant. The surface of the metal is covered with thin coat of wax, asphalt, or varnish, called etching-ground, which is scratched with the etching needle where lines are desired, and the exposed part subjected to acid, which then creates incised lines in the surface of the plate. The plate is dipped in acid repeatedly to bite out the design. The process forms the foundation of photogravure.

Etching Revival

A name contemporaneously given to the period of time approximately from 1850 to 1930, during which a renaissance of etching as a form of printmaking was seen. Artists producing work during the so-called Etching Revival did so in the spirit of old master printers.

Ferric Chloride

An etching agent used in progressive concentrations during the etching of a photogravure plate.

Flatbiting

In etching, flatbiting refers to an area of a print intended to be black which, despite being deeply etched, has lost its dot pattern and cannot hold ink. Flatbiting prints are typically an irregular gray with dark edges and are commonly seen in early photogravure experiments and test.

Follygraphique

A photolithographic method by invented by Charles Jules de Lafollye. HCL 78

Foxing

Warm colored stains or spots appearing randomly on old prints, caused by chemical composition of the paper and its reaction to the environment.

Genre

A pictorial or narrative representation of scenes or events of everyday life.

The Gilded Age

A term used to describe a period of rapid economic growth in United States history from approximately 1870 until 1900. The period is marked by an influx of immigrants from Europe, the expansion of industry, such as the railroad, factories, mining, and finance, and a concentration on accumulating wealth.

Gillotage

Invented circa 1850 by Firmin Gillot (French), gillotage was a method of making relief metal plates for letterpress printing and printing illustrations in books and periodicals. Part of the etching process, the technique involves making a lithographic drawing on zinc, dusting the plate with an acid-resistant resin, and then submerging the whole plate in acid, thus resulting in a relief block. Gillot’s son is often credited with combining photography with the printing technique. HCL 61

Gillotype

A printing process using a zinc plate created by a photographic transfer. Invented by Mr. Gillot in 1872. Also called paniconographie.

Glyptotype

An electrotype process where a copy is obtained from an engraved plate by creating a raised surface of gelatin suitable for letterpress printing.

Goupil Gravure

The variant photogravure process perfected in 1872 by Henri Rousselon of Goupil & Cie in France. Goupil gravures, used by the company to make art reproductions, allowed for a deep, velvety black, the separation of tones, and a crisp image. HCL 121-22

Gradation

In the graphic arts, gradation means the gradual transition from one tone to the next. The more finely distributed the points, the more continuous the change in tone is.

Gravure

A type of intaglio printing process in which ink is transferred under pressure from the recessed areas of an incised plate. The transfer of ink produces a finely detailed, sharp image. Gravure is also an alternative name for both photogravures and rotogravures.

Gravure Héliographique

An early photoengraving process invented by Niépce de Saint-Victor. The process introduced the revolutionary use of asphalt, however, besides reproducing basic lines, the gravure héliographique only had limited success rendering images with subtle tonal densities or shading. HCL 97-8

Ground

A ground is a coating applied to a printing plate to protect it from the action of the mordant used in etching. In photogravure etching, the ground acts as to create the grain structure that allows for the representation of continuous tone.

Gum-Bichromate Print

The gum-bichromate process was popular among pictorialists like Edward Steichen and Robert Demachy for its painterly qualities. Gum prints are produced by brushing onto a sheet of textured paper a gum arabic solution mixed with potassium bichromate and a suitable pigment.  When dry, the sheet is exposed in contact with a negative. The print is then developed during which time the photographer can manipulate the print with a brush, sponge or spray of water. Multiple gum prints, usually more than one color, are made by additional printings of the same negative in register on the original sheet.

Gum-Platinum Process

Also called gum over platinum, the gum-platinum process is a combination of the platinum and gum-bichromate processes, in which a platinum print is coated with bichromated gelatin before a gum-bichromate print in placed on top in register. Because of the painterly quality of the prints, this technique was used by many pictorialists of the early- twentieth century, such as Edward Steichen and Alvin Langdon Coburn.

Gypsography

The process of engraving on gypsum, casting a plate using the plaster as a mold, and printing it in relief.

Halftone

A term used to describe a series of sized dots making up the continuous tonalities of photographic prints or negatives. Similarly, the halftone process is a method of mechanical printing the series of dots for the mass production and reproduction of photographic images.

Hashira-e

A tall and narrow Japanese woodblock print often hung in tryptics on interior pillars for decoration. The format was adopted by several turn-of-the-century pictorialist photographers, including Alfred Stieglitz and Thomas Annan

Heliochromie (Heliochromy)

A process devised by Niépce de Saint-Victor between 1849 and 1852. The process involved the direct exposure of a silver plate coated with silver chloride, which had been dipped in a weak solution of sodium hypochlorite, followed by lead chloride in dextrin. From this process, Niépce de Saint-Victor obtained colored reproductions of various subjects, like a bouquet of flowers, a stained glass window, and dolls with different types of clothing. However, the images were never adequately fixed and the colors soon faded.

Heliography (Heliograph)

The process developed by Nicéphore Niépce circa 1822 to produce the first permanent photographic images. The process relies on the photosensitive properties of bitumen of Judea. Niépce’s experiments with heliography began on silver-plated copper sheets, items used by engravers, thus making evident his intention to create a process that allowed for the mass production of an image in a similar manner to engravings.  It consists essentially in exposing under a design or in a camera a polished metal plate coated with a preparation of bitumen of Judea, and subsequently treating the plate with a suitable solvent. The light renders insoluble those parts of the bitumen which it strikes, and so a permanent image is formed, which can be etched upon the plate by the use of acid.

Heliogravure

A generic name for photogravure in France. The photomechanical process that employs light sensitive asphaltum to create a resist for directly etching metal or pewter plates for printing positives on paper. The process was first discovered by Nicéphore Niépce, and perfected in many variants throughout the 1800s.

Hélioplastie

An etching process developed in 1855 by Alphonse Poitevin based on the photosensitive and swelling properties of dichromated gelatin

Heliotype

A collotype process developed, patented, and introduced by Ernest Edwards in 1869. Edwards’s technique involved adding chrome alum to the gelatin as a hardening agent. The process was used for book illustrations.  HCL 49

Hyalography (Hyalograph)

From Greek words for glass and print, a process invented by M. Dujardin for making photographic etchings on finely polished glass. An artist would draw on the glass plate with a lead pencil, stump, or brush with India ink. The drawing would then be transferred by light to a metal plate covered with a sensitized etching ground. This metal plate would be washed and etched after exposure, and finally printed, resulting in an impressive print with fine tones.

India Paper

A thin yellowish absorbent printing paper made in China and Japan from vegetable fiber and used in taking the first and finest proofs from engraved plates.

Intaglio

Intaglio refers to any printmaking technique in which an image is incised into a surface. The surface of the intaglio plate is inked with rollers and then wiped clean, the remaining ink staying in the recessed lines. One of the early problems with intaglio printing was that wiping the excess ink tended to remove ink from large shadow areas. The problem was solved by dusting and melting a solution of resin on the plate (a ground), thus marking the beginnings of the aquatint process. The ground of melted resin provides tooth or roughness to hold the ink during wiping.

Japanese Paper

High quality paper usually composed entirely of gampi.  The color of the paper ranges from a golden yellow to buff. Their weight ranges from 100 to 200 grams per square meter. 

Kallitype

A photographic process invented and perfected by W. J. Nichols in 1889. Similar to Van Dyke printing, the process is based on the combination of photosensitive iron salts and silver salts. The negatives are contact printed and the exposed prints are developed-out in sodium citrate. Chemically, when toned with platinum or palladium, this process is almost identical to Plainotypes. Visually, kallitypes are similar to platinum prints, given their rich tonal ranges

Leggotype

A high-volume photomechanical reproduction technique. William A. Leggo, working with George E. Desbarats, created and patented the Leggotype in 1865 by combining elements of Pretsch’s swelled-gelatin method with a single-line screen. This early halftone process appeared in Canadian Illustrated News and L’Opinion publique, but it was printed lithographically, separately from the text. HCL 79-80

Leimtype

A variation of the photo-etching and collotype processes patented by Professor J. Husnik of Prague in 1887. The process involves exposing a layer of bichromated gelatin that has been fastened to a metal plate with resin, and then developing the exposed plate with a solvent.

Lemerciergravure

A photomechanical process based on the chemical properties of asphalt. The process was perfected in 1852 by the French printer Rosé-Joseph Lemercier of the largest lithographic firm in 1880s Paris, Lemercier et Cie.

Levytype

A photochemical engraving process jointly invented and patented by brothers Louis Edward Levy and Max Levy in 1875. To produce the photo-relief plates used for printing, the Levytype process involved taking a photograph on a prepared plate, which was then chemically treated so that the parts of the plate not acted upon by light rise, as opposed to the lines of the image. A plaster cast was then taken from the treated plate to be used for printing. HCL 83

Lichtdruck

A term first used by the German lithographer Max Gemoser in 1868, a “Lichtdruck” is a variation of the collotype process. This process allowed for the first reproductions using halftone illustrations to appear in German publications, beginning in 1870 and lasting until 1900. Lichtdruck, which translates to “light print,” still remains the common term for collotype prints in Germany. Lichtdruck is a method of printing photographs in an ordinary lithographic press, with printer’s ink, from gelatine films prepared on the same principle as the Woodbury tissue, except that the soluble gelatine is not washed away. The film is attached to a thick plate of glass fixed in the press, and when sponged over, the soluble parts absorb water, and so are prevented from taking on ink, while the insoluble portions remain dry, and the ink adheres to them. Also called Phototype or Phototypie (in France). HCL 58

Linograph

Comprised of the words lithos, meaning “stone”, and graph, meaning “to write”, linograph refers to the process of printing from a stone, mostly lithographic limestone, and is based on the immiscibility of oil and water. Can also refer to an early Austrian process of photographic printing onto woven fabrics and textiles.

Linotype

A typesetting machine invented in 1884 that allowed lines of characters to be printed all at once as opposed to just a single character at a time. The Linotype revolutionized the way in which newspapers and periodicals were printed and remained the dominant typesetting machine until the 1970s

Lichtkupferdruck

First discovered by Johann Baptist Obernetter in 1883, the Lichtupferdruck process is a light-copper printing photogravure method. It entails converting the silver within a positive film made of gelatino-bromide into silver chloride. This is achieved through the mixture of perchloride of iron and chromic acid on the film. Next, the film is stripped and applied to the surface of a copper plate which, under the influence of a voltaic current, is etched. Depending on the depth of the deposit of silver chloride on the copper plate determines the depth of the incised etch. The result is a finely grained intaglio plate, which is inked and printed the same way as any other intaglio plate. Production of photographs though the Lichtupferdruck process appears to have terminated with Obernetter’s death in 1887. HCL 99-100

Lithophotographie

A French photomechanical process based on lithography and developed by the partnership of Rose-Joseph Lemercier, Noel Lerebours, Barreswill, and Alphonse Davanne. It was first reported to the Académie des Sciences by Francois Arago on August 16, 1852 and was patented on August 25, 1852. The process is rooted in Niepce’s early photographic discoveries. In lithophotographie bitumen of Judea is poured onto a lithographic stone. A negative is then placed onto the stone and exposed to light. The areas that receive light harden, thus when the stone is washed with acid it is able to incise the places of the stone where no hardened bitumen covers. Finally, the stone is inked and pressed onto a sheet of paper. HCL 81

Litho-heliogravure

Invented by Charles Eckstein, of the Typographical Bureau of the Royal Netherland Staff, litho-heliogravure is a photo-lithographic process. The details are precisely similar to those employed in the process of machine photogravure, excepting that, instead of copper, a lithographic stone is used and printed from in the lithographic manner.

Lithography

The art and process of creating an image upon a stone surface utilizing the immiscibility between oil and water. It requires a greasy image on a surface of smooth limestone to be moistened and then inked; the image then repels the water but accepts the ink, while the stone accepts the water and consequently repels the ink.  Although the printing process was discovered in 1798 by Alois Senefelder of Munich, it first became popular in the 1820’s in order to illustrate publications.

Lithotype

An etched stone surface for printing, having the design in relief.

Little Galleries of the Photo-Secession

Also known as 291 Gallery (named after the gallery’s location at 291 Fifth Avenue), the Little Galleries of the Photo-Secession were created by Alfred Stieglitz in 1905 and remained open until 1917. Not only did these galleries aim to elevate photography as a definite form of fine art, exhibiting photographs by such Photo-Secession members as Edward Steichen, Alvin Langdon Coburn, Gertrude Käsebier and Clarence H. White. but they also introduced America to modernist European avant-garde art movements, seen through the inclusion of such artists as Auguste Rodin, Henri Matisse, Paul Cézanne, Pablo Picasso, Constantin Brancusi, and others

Manual Print

Type of print whereby the image was created directly on the printing surface, for example drawn directly onto a wood block.

Mezzogravure

An intaglio engraving process possessing characteristics of both steel engraving and photogravure, with the method of reproduction and finished print more in line with photogravure techniques. The process uses intaglio engraving and a supplement of special machinery, such as rotogravures or sheet-fed mechanized gravure, by which prints can be produced rapidly and at a lower cost than traditional photogravure. Mezzogravure allowed for a great range of colors to exist within the finished prints, contrasting with the usual monotone style of photogravure. This process was heavily developed and practiced by the Mezzo-Gravure Company from New York.

Mezzo Tinto Gravure

A variation of the photogravure process invented by Austrian born Theodor Reich in around 1897. The process utilized both a cross-line screen in addition to flat-plate gravure, which allowed for prints to be made from the use of a single plate that could be wiped with a doctor blade, thus speeding up the printing process. The Mezzo Tinto Gravure process was sold by Reich to F. Bruckmann of Munich in 1903. The process was used and advertised until approximately 1927. HCL 118

Mezzotint

A printmaking process of the intaglio family invented in Holland in the 1600s by German-born Ludwig von Siegen. The word mezzotint comes from the Italian “mezz tinta,” meaning “halftone,” which refers to the processes ability to produce wide and subtle variations of tone. Technically a drypoint method, the mezzotint process is able to produce such a variety of tones by roughening the plate with thousands of little dots made by a metal tool with small teeth, called a “rocker.” In printing, the tiny pits in the plate hold the ink when the face of the plate is wiped clean, enabling a high level of quality and richness to be found within the print. It was the first tonal method to be used, enabling half-tones to be produced without using line- or dot-based techniques like hatching, cross-hatching or stipple, however greater definition is given to mezzotints through the incorporation of additional etched or engraved lines. Although popular throughout the 17th, 18th and majority of the 19th century for the reproduction of artworks, the dominance of mass-produced photographic reproductions towards the end of the 19th century made the mezzotint process practically obsolete.

Mezzotype

Also called “mezzotint in relief,” mezzotype is an engraving process that was developed in Germany. It provided a means for reproducing drawing and photographs by reversing the traditional process of making a photogravure block. Rather than using a positive when producing the intaglio plate, mezzotypes require a reversed negative, which allows the highlights to be bitten away as opposed to the shadows of the photograph.

Missions Héliographiques

A photographic survey commissioned in 1851 by the Commission des Monuments Historiques, an agency of the French Government, in order to record historic French landmarks, monuments, and other architectural structures that were either in the process of restoration or with the aim of being restored. It possesses the notable distinction of being one of the first uses of photography by a government agency for archival purposes. The goal of the project was to aid the Paris-based commission in determining the nature and urgency of the preservation and restoration of work required at historic sites throughout France. The selected photographers—Édouard Baldus, Hippolyte Bayard, Gustave Le Gray, Henri Le Secq, and Auguste Mestral—were all members of the fledgling Société Héliographique, the society. Each was assigned a travel itinerary and detailed list of monuments: Baldus was sent south and east to photograph Provence, Burgundy, Fontainebleau, and the Dauphine; Bayard was sent west to Normandy; Le Secq was assigned the north-east region of Champagne, Lorraine, and Alsace; Le Gray and Mestral travelled and photographed together to both central and southwest France, covering the regions of the Loire Valley, Languedoc, and finally Auvergne. Although the survey culminated in almost three hundred photographs depicting French heritage, none of them were ever published or exhibited by the Commission

Moss-Type

A photoengraving process developed by John Calvin Moss in 1885, in which a gelatin relief plate is used to create a plaster or wax cast. This cast was then the basis of a plaster mold that ultimately helped create a cast made of stereotype metal. This metal-based cast produced halftone prints. Moss opened the Moss Engraving Company in 1880, which was one of the first successful photoengraving businesses in America. HCL 93

Nature Printing

A printing process that applies ink to the physical objects themselves, traditionally natural specimens such as leaves, flowers, rocks, etc., and pressed directly onto paper or an intaglio plate. While this technique was first practiced in the Middle Ages, it was further developed and mastered by the Austrian printer Alois Auer, who published a book in 1853 entitled The Discovery of the Natural Printing Process: an Invention. HCL 11

Newspaper Photogravure

First developed by Dr. Mertens and implemented within the German newspaper Freiburger Zeitung in 1910, newspaper photogravure applied the intaglio printing process of traditional photogravure to producing newspaper illustrations. It allowed for cylinder-shaped intaglio plates to reproduce not proper photogravures, as the name implies, but rather halftone engravings. These engravings were produced at high speeds and with accompanying text. The process was superseded by rotogravure in 1912.

Nōtan (濃淡)

A Japanese design concept involving the balance and placement of light and dark as they are placed next to the other in art and imagery.

Oil Pigment Process

A printing process discovered by G. E. H. Rawlins in 1904, which was based off of photographic techniques explored by such innovators as Poitevin and Pouncy forty and fifty years earlier. The process called for a piece of gelatin coated paper to be brushed with a bichromate solution and then exposed under a negative. The paper is then immersed in water, which allows areas of the bichromated gelatin to swell and absorb the moisture according to the amount of exposure received under the various tones of the negative. The parts of the print that received the most light (shadows) will be rendered insoluble, while the parts that received the least light (the highlights) will be rendered soluble. Next, the paper is removed from the water and brushed with an oil-based pigment, which is absorbed only by the insoluble gelatin and repelled by the water clogged soluble gelatin. This process was popular amongst the Pictorialist photographers.

Paniconographie

A photomechanical plate-making process created by the Frenchman Firmin Gillot in 1850. The process yielded a relief plate that was made of zinc and that was etched with acid. In 1872 Gillot’s son, Charles Gillot, with the help of Daniel Verge, refined this process, allowing images to be photo-mechanically transferred to the zinc plate through a method of inking, dusting, and heating the relief plate. Paniconography was revolutionary in its ability to be combined with typographic letters and subsequently run through the same press, allowing the seamless integration of image and text within a single impression and providing an increase in mass-reproduction. The French photographer Charles Negre utilized this process for his one of his printed photographs found within the periodical La Lumiere in 1855. HCL HCL 61

Pannotype, or Panotype, Panotypie (French)

A collodion silver photograph transferred onto a support of waxed textile fabric, first developed in 1853 by the photographic firm Wulff and Co.

Papyrotype

A photolithographic process invented by photographic innovator Capt. (later Sir) W. de W. Abney at the School of Military Engineering, Chatham, UK, in approximately 1871. The process requires a piece of paper to be coated with bichromated gelatin and then exposed to light beneath a negative. The paper is then developed with cold water, coated with a greasy ink, and then transferred to a stone or metal plate for lithographic printing.

Photo-Aquatint (Photoaquatint)

The name given to what we understand today as the photogravure process. An aquatint made by a photomechanical process that involves the mixing of carbon with gelatin, exposing a film of this on a plate, and washing it out. The film is then laid on an aquatint ground, usually with a continuous tone negative film on top, after which the plate may be etched. This term was first used at an exhibition of photo-technological methods at the Boston Museum of Fine Arts in 1892. This is due to the fact that photogravure is essentially based on the properties of the aquatint process, in which the reticulation of a powder (resin) on a metal plate provides a wide variety of dot structures which are etched with acid to produce an intaglio printing plate. “Photo-aquatint” is also the term used in Alfred Maskell and Robert Demachy’s 1897 publication entitled Photo-aquatint, or, The gum-bichromate process : a practical treatise on a new process of printing in pigment especially suitable for pictorial workers. Although the name “photo-aquatint” did not last, the process certainly did.

Photochromie

An intricate photomechanical color printing method that combined both chromolithography and Woodburytype processes. Developed by engineer, writer and photographer Leon Vidal (1834-1906) in the early 1870s, the process involved multiple color separations printed under a transparent woodburytype black layer. It was mostly to illustrate art objects, such as within the sumptuous publication Tresor Artistique de al France, published in both 1872 and 1875. The complex process was notable for its remarkably realistic reproduction of metals such as gold and silver. It should not be confused with a number of other processes also marketed under the same name later in the nineteenth century.  HCL 138

Photo-Club de Paris

Organized in France in 1888 by Maurice Bucquet, the Photo-Club de Paris provided an alternate photographic society to the primarily technical, scientific, and commercial oriented organizations of the time. The members’ sole purpose was to discuss and promote pictorial photography as an art and bestow photographers with the title of artist. In 1894, the Photo-Club de Paris organized their first exhibition, entitled Premiere exposition internationale d’art photographique du Photo-Club de Paris. Notable members of the club included Robert Demachy, Rene Le Begue and Constant Puyo, all of which were practitioners of hand manipulated painterly printing techniques. As interest in pictorial photography declined, the club dissolved in the early 1930s.

Photo-Electrotypes

An electrotype plate formed in a mold made by photographing on prepared gelatin. This process allowed for original plates to be remain unused by creating copy plates.

Photoengraving

A photomechanical printing process in which an image is printed onto a plate through the use of a photoresist. The resulting printed image on the plate dictates where areas of the plate should be removed, either chemically or manually,  or remain in order for the correct tonal values to be obtained within the finished print. Principles of photoengraving can be applied both to relief and intaglio printing methods. In the case of photogravure, hardened gelatin acts as the photoresist. This layer protects the white highlights of the finished print by blocking the ferric chloride from penetrating the copper plate. The ferric chloride, however, is able to easily bite the uncovered areas of the plate and incises into them first. These become the darkest areas, or shadows, of the resulting print.

Photoetching

A photomechanical printing process that utilizes photoengraving for the production of an intaglio plate, such as photogravure. This action of light on bitumen accounts for the earliest successful permanent reproduction of the camera picture by Joseph Nicephore Niepce in 1824.

Photogalvanography

An early successful photomechanical engraving process developed and patented by Paul Pretsch in 1854. The process used electricity to etch into the copper plates. These plates were later called photoelectrotypes. Pretsch’s photogalvanographs were used in the production of Photographic Art Treasures (1856), the first publication devoted to the art of photography. Dallas supposed modification, called the Photo-electric Engraving, was copied from Pretsch’s Photogalvanograph. HCL 114

Photoglyphic Engraving

Talbot’s final patent of 1858 which modified his technique of photographic-engraving adding aquatint resin ground over the hardened gelatin rather than rinsing it, thereby increasing the tonal range. He also began etching in Ferric Chloride. This process would become the basis of the Klic’s photogravure method, which is understood today as the Talbot-Klic process. HCL 129-30

Photoglyptie

The French equivalent of the Woodburytype, which was invented in 1864 by Walter Bentley Woodbury. The process entailed placing a positive bichromated gelatin relief image into a hydraulic press, which produced a relief mold of the contours of the different densities within a given photograph. The printers French Goupil et Cie. bought the patent from the inventor for 150,000 francs in 1867, and exploited it commercially under the name photoglyptie

Photolithograph (Photolithography)

An image formed photographically is printed from a lithographic stone. The art, process or operation of producing on stone, largely by photographic means, a printing surface from which impressions may be taken by a lithographic process.

Photo-mezzotype

A photo-mechanical printing process similar to collotype. The name ‘Photo-mezzotype’ was registered by the London Stereoscopic Company, in which they claimed that the collotype process was improved and better suited for high-end reproductions of paintings, portraits, and fine art objects.

Photo-Secession

Founded by Stieglitz in 1902, the Photo-Secession was a group of prominent photographers who promoted a break from the conventional and popular photography organizations of the early twentieth century. The movement championed pictorial photography and the subjective vision that it entails in order to establish photography as a legitimate fine art. Prominent members included F. Holland Day, Gertrude Kasebier, Edward Steichen, Clarence H. White, Frank Eugene, and Alvin Langdon Coburn. Work by such Photo-Secessionist photographers was praised in Stieglitz’s periodical Camera Work and exhibited at his 291 Gallery.

Photogenic Drawing

Invented in 1834, Photogenic Drawing was William Henry Fox Talbot’s first photographic process, which he announced publicly in 1839. The process entailed coating light sensitive silver salts onto plain writing paper. This was then exposed either in a camera or directly in contact under an object such as a leaf. Where the light reached the surface, the energy reduced the salts to finely divided silver. This produced a negative, which could then be fixed. The same type of paper could be exposed under a negative to reverse things again, making a positive print.

Photographic Engraving

William Henry Fox Talbot’s first photomechanical process, patented in 1852. A gelatin and dichromate mixture was coated on a metal plate, dried, and then exposed under an object or a photographic positive. The coating was hardened wherever light reached it, forming a mask (or resist). The plate could then be etched with a platinum solution and washed. The pits that were created could receive printing ink and the plate printed in a conventional press.

Photographic Veil

Talbot’s term for the screen of gauze or net that he impressed upon a sensitized steel plate prior to exposure in order to hold ink in broad areas of tone.  The first application of a halftone screen.

Photogravure

A means of reproducing a photograph by printing on paper from an etched and inked copper plate. The most successful method introduced by Talbot in 1852 and perfected by Karl Klíč add in 1879, the process came into general use in the 1890s for high-quality photographic reproductions.  Over time, photogravures have become increasingly valued as works of fine art. Today photogravure is considered one of the finest and most time intensive of the photographic processes.

Photolithography

A photomechanical printing process based on lithography, which utilizes the mutual repulsion of oil and water. Using lithographic techniques in the creation of photographs was first explored by Joseph Nicephore Niepce, who applied photosensitive bitumen dissolved in essential oil of lavender onto a lithographic stone. However, Niepce abandoned the method in favor of heliographic etching on metal. Lemercier, Lerebours, Barrswill and Davenne of Paris refined Niepce’s process in 1852, who similarly coated a solution of bitumen dissolved in ether onto a grained lithographic stone. Once the solution was dry, the stone was exposed underneath a paper negative and washed, so as to remove the unexposed areas of soluble bitumen. The stone was then processed with gum Arabic, etched and rolled up in ink for halftone prints to be made. It was finally in 1855, when Alphonse Poitevin replaced the bitumen with potassium dichromate and albumen, that our present day understanding of photolithography was achieved. Poitevin’s photolithographic techniques lead directly to the discovery of photolithographic transfer, chromolithography, and photozincography.

Photomanual

A term used that is in opposition to photomechanical processes.

Photomechanical prints

A generic term used to describe an early application of photography to the print industry; it denotes a process where the action of light upon chemicals on a prepared surface, such as a plate, allows for the printing of a photographic image in ink.

Photo-mezzotint

The name given by Joseph Wilson Swan to his photo-relief process, which is nearly identical to the Woodburytype process. Although it was conceived earlier than Walter Bentley Woodbury’s process, it wasn’t published until after Bentley’s 1864 public announcement of the Woodyburytype.

Photorelief

A photoengraving created for use on a typographic press.

Phototypie

French term for collotype.  Also the original term for used Tessié Du Motay et Maréchal’s process.

Phototype

Can refer to a metal printing block, sometimes prepared using the photogravure process, to reproduce a photograph. Phototype can also refer to type set using a phototypesetting process in order to prepare pages for photolithography. This process replaced hot metal typesetting and was commonly used in the late nineteenth century (for book illustration), and through the 1970s and 1980s. After the 1980s, it was rendered obsolete by modern systems which employ a raster image processor to render an entire page to a single high-resolution digital image which is then photoset.

Photoxylograph

An early photoengraving process (from the mid-1850s) that utilized the production of a photographic image on photo-sensitized boxwood blocks as a guide for the engraver’s knife, instead of using an image drawn by hand on the wood block.

Photozincograph

Sometimes referred to as heliozincography, photozincography is a photomechanical process developed by Sir Henry James FRS in the 1850s. The process allowed for photographic images to be transferred to a zinc plate for printing. The use of zinc allowed the surface to be slightly etched with nitric acid to enhance the quality of the resulting image.

Photozincotype

A plate prepared for printing by photozincography.

Physionotrace

An instrument invented by the Frenchman Gilles-Louis Chretien in the 1780s, the physionotrace was used to capture a sitter’s profile, also known as their physiognomy, on a sheet of paper. Existing before the invention of photography, this device allowed people to acquire silhouette portraits of themselves that was quick, cheap,mechanically precise and reproducable. A forerunner of portrait photography.

Pictorial Photography

A photographic movement that attempted to redefine the photograph as a legitimate form of fine art. In the late nineteenth and early twentieth centuries, Pictorial photographers aligned their practice with more painterly aesthetics and subject matters, concentrating more on hazy, atmospheric effects and personal, subjective expression. Emphasis was also placed upon on the artistically rendered print, that was usually heavily manipulated in order to show the artist’s hand.

Pigment Processes

Planar plates were the basis of lithography, which used flat porous stones that retained greasy inks and repelled water. It was not directly compatible with type, but type impressions in greasy ink could be used along with a picture impression by using transfer paper.

Platinum

Although platinum was first explored by both Sir John Herschel and Robert in the creation of photographic images in the late 1830s and early 1840s, it was not until 1873 that Englishman William Willis Jr. was able to effectively experiment with platinous salts. Although such photographic innovators as Giuseppe Pizzighelli and Baron Arthur von Hubl introduced printing-out platinum papers in the late 1880s, Willis perfected the platinum process that we are familiar with today in 1893. Also called platinotypes, platinum prints offer delicate gradations and a velvety surface most closely resembling photogravures, the platinum printing process was popular with pictorial photographers from the 1880s through World War I. For platinum prints, paper is coated with a solution of iron salts and a platinum compound. The paper, much admired for its permanency, was contact printed until the image was slightly visible and then developed to the desired density.

Plumbeotype

The name given by John Plumbe in the 1840s to the hand drawn lithographs that he made from his daguerreotypes.

Poitevin's Carbon Process

The carbon process was implemented by Alphonse Louis Poitevin in 1855, which drew upon the experiments of both Mungo Ponton and William Henry Fox Talbot with the light sensitivity of dichromated gelatin in order to achieve a permanent pigment print. Poitevin’s carbon process called for a negative to be printed onto a tissue composed of pigmented gelatin as well as potassium dichromate. The tissue was washed, and then transferred to another sheet of paper, resulting in a stable and rich print.

Polyautographic

A print produced by lithography, in which multiple reproductions can be created.

Potassium Bichromate

Light sensitive compound that hardens when exposed to light and resists acid during etching. Bichromate of potash, as potassium dichromate was known in the early 1800s, and still is in the USA, has major connections with Glasgow.  It was also known as bichrome and chromate of potash. It was originally made by heating chromium iron ore with saltpetre (potassium nitrate). It was a key component in the production of dyes for calico printing: yellow, orange, green and brown dyes all depended on it.  Glasgow, along with Lancashire were the two main centers of production in the world.

Potassium Dichromate (M. Ponton)

The light sensitive properties of this compound were discovered by the Scottish lawyer and inventor Mungo Ponton and presented to the Society of Arts in Scotland in 1839. Ponton showed that paper that was soaked in a potassium dichromate solution, and then left out in the sun, would tan, or darken over time. Although this proved to be a major breakthrough in the quest for a more permanent photograph, Ponton decided not to patent his discovery but rather encouraged others to experiment with potassium dichromate. By doing so, he allowed such photographers as William Henry Fox Talbot, Edmond Becquerel, Alphonese Louis Poitevin, John Pouncy, and Joseph Swan to incorporate potassium dichromate into their photographic experiments. This resulted in the creation of such photomechanical processes as gum bichromate, carbon printing, and photomechanical processes such as photogravure, Woodburytype, Autotype, and collotype. HCL 112

Pre-Raphaelite Style

An English art movement beginning in 1848 that challenged the dominant nineteenth century perception that classical Renaissance masters, such as Raphael, represented the ideal manner of artmaking. The Pre-Raphaelites, rather, sought out poetic subject matters drawn from literature, history, religion, and mythology and rendered them in a more realist manner. Notable members include William Holman Hunt, John Everett Millais, and Dante Gabriel Rossetti, as well the photographer Julia Margaret Cameron. The movement would influence other early twentieth century art movements such as Symbolism.

Provenance

The history of ownership of a work of art. A full provenance is able to prove previous ownership, definitively assign a work of art to an artist, and establish a works authenticity.

Printer’s Ink

Ink used in the creation of photomechanical photographs. They fall into two categories: water based and oil based. Water based inks come from colloidal carbon in water. They are thinner than oil based and thus are able to soak into paper easier and dry quickly. Oil based inks are used when printing with intaglio plates. They are greasy, thick and dry slowly.

Pyrogravure

The art of engraving on wood and other substances by fire—that is, with pieces of metal more or less in the shape of pencils, and heated red.

Recto

A right-hand page of an open book or manuscript. Also the front of a leaf (opposed to verso).

Relief Process

A photomechanical printing process in which the inked areas are raised above the clear areas and can be printed on the same press as ordinary raised letterpress type.

Rembrandt Process

A development of Karel Klíč’s photogravure process that allowed for the mass-production of high quality screened gravures from curved printing plates, which Klic called rotogravure. It is referred to as the Rembrandt process due to the fact that Klic, along with his collaborator Samuel Fawcett, was able to convince the Storey Brothers in Lancaster to transition their company from printing textiles to printing high quality gravures from rotary intaglio plates. The new company, established in 1895, was called the Rembrandt Intaglio Printing company and was the first to produce rotogravures. HCL 75

Reticulation

A microscopic worm-like pattern in gelatin emulsions resulting from rapid and extreme temperature changes in solution, or drastic acid-alkaline cycling. It is a damage condition that is sometimes used for special effects. It was deliberately used in the collotype process to produce a random screen for halftone printing.

Retossuage

Coating a thin film of ink from the etched intaglio up onto the surface of the plate, which could then be rubbed and wiped for greater expressive effect. This added to the otherwise linear etching a variable mid-tone

Rotogravure

A rotary gravure process developed by Karel Klic and Samuel Fawcett in 1895, in which prints could be made more rapidly than the traditional photogravure process and from rotating intaglio copper cylinders that inked mechanically. In the rotary process the photographic print is taken through a cross-lined screen, which has the effect of breaking up the picture into a pattern of very small squares. It also made use of a doctor blade, which wiped the excess ink off the plates surface after each print. This process is also referred to as sheet fed photogravure.

Sandell Cristoid Film

A film patented in 1899 made up of two or three distinct layers of emulsions of different speeds. Used by Alvin Langdon Coburn and Frederick H. Evans to achieve atmospheric effects and increased tonal range.

Screen Gravure

A film or sheet of glass that is made up of transparent lines that when crossed at right angles, create opaque squares. Screen gravures are used in rotary printing in order to allow for a support for the doctor blade, which wipes ink from non-printing areas. The lines additionally provide for light to go pass them to access the film and harden the gelatin underneath, while the opaque squares stay soft.

Similigravure

The French term for letterpress halftone. Originally the term used for Charles Petit’s relief halftone process, but ultimately became a generic term for letterpress halftone in France.

Sprague's Ink Process

One of the first commercially available photolithographic process that could reproduce tone, as opposed to just line, the ink-photo process was developed by the London firm Sprague & Co. in the early 1880s. It was first revealed at the exhibition of Photographic Processes and Appliances, held at the home of the Society of Arts in 1882, and was called “Specimens of Ink Photo Process, a New Method of Reproducing the Gradations of Tint in Photographs by Photo-Lithography.” The process was a transfer lithograph that utilized the reticulation of gelatin in order to divide the image into tiny squiggles, which was then transferred to a printing stone or zinc plate. Although similar to the collotype, Sprague’s ink process was considerably cheaper and easier to produce prints, however they did not yield as high-quality prints. HCL 127

Stannotype

Patented in 1879 by Walter Bentley Woodbury, a Stannotype is a simplified form of the Woodburytype process of photo-mechanical engraving. The process calls for a gelatin relief image to be prepared as with the Woodburytype process, but with the Stannotype the relief is made from a positive and not a negative. The gelatin image is faced with tinfoil to form a mold which is used in a similar manner as the lead mold in the Woodburytype process. The Stannotype process obviates the use of a hydraulic press essential for the production of Woodburytypes. However, many amateur photographers found the creation of gelatin relief molds as difficult and time consuming. It was not so extensively adopted as the Woodburytype process.

State(s)

Two prints are of different states if they were made from a plate which was altered (e.g., adding more lines onto an etching plate) after the creation of an earlier impression. The first series of impressions is called the first state; the next the second state, etc.

Steel Engraving

A popular intaglio printing technique used from 1820 to 1880, steel engravings were developed by the American Jacob Perkins in 1792 and adapted by the Englishmen Charles Warren and Charles Heath beginning in 1820. The switch from copper to steel was due to the fact that steel plates were harder than copper, which allowed for more reproductions to be made from a single plate. Steel also made it possible to engrave much finer detail that would have worn the softer copper plate. However, this also made it more difficult to actually cut into the plate itself and required a change in engraving methods and the use of finer, harder tools. Once electrotyping was discovered, in which copper plates could be coated with steel, also known as “steel-facing” or “steel-plating”, the popularity of steel engraving plummeted.

Steel Facing

A process using electrolysis to coat an intaglio copper plate with a fine layer of iron. This steel coating effectively extends the life of the printing plate, allowing the soft copper to be reinforced by the steel in way that prevents the wearing away of the copper and thus the impressions it produces.

Stopping Ground

A mixture used in Etching, made of lampblack and Venetian turpentine.

Straight Photography

Departing from the painterly manipulated techniques of the pictorialists, the straight photographer promoted an aesthetic of photography that privileged inherent characteristics of the medium itself. This more modern interpretation of photography relied on sharp, detailed prints and a seemingly objective and formal approach to subject matter. This straightforward approach was touched upon by Alfred Stieglitz, but is typically attributed to Paul Strand, more specifically to his photographs in the final issues of Camera Work. In many ways was the catalyst that separated photography from the other visual arts and established it as a valid medium in its own right. Famous straight photographers to follow Stieglitz and Strand include Edward Weston and Ansel Adams.

Tableaux

Narrative tableau – the representation of models, props and sets arranged to tell a story – is a technique employed by painters and photographers. It appealed to the expanding middle-class and urban audiences in the nineteenth century who were enjoying the literature of prints, illustrated books and journals, reaching a broader public through
 new markets in Britain and abroad, especially in America and the British Empire.

Taille-douce

French word for ‘intaglio.’

Talbotype

An alternate name for Calotype, which is the photographic process invented by William Henry Fox Talbot in September 1840 and patented in February 1841. It required a plain sheet of writing paper to be dipped in potassium iodide and coated with a solution of silver nitrate. This formed silver iodide when dried. The paper was then floated on a mixture containing silver nitrate and Gallic acid. After exposure, this paper negative was usually waxed for transparency and used to make salt prints.

Teinte a la Paume

Tint that’s left on the plate to add tone and a unified structure.

Tonalists

The Tonalists were members of the art movement Tonalism, which spanned from the 1880s to the 1920s. In its early days, Tonalism was primarily comprised of painters who rendered landscapes in a limited palette of subtle, muted colors that attempted to capture the true atmosphere of a given scene. Musical compositions provided a strong influence on this movement, in that painters tried to communicate the inner harmony and expressive emotions within a painting. Pictorialist photographers aspiring towards the perception of photography as a fine art medium utilized the principles/aesthetics of the tonalist movement, imbuing their works with a similar gauzy atmosphere through soft focus and limited contrast, favoring a reductionist tonal palette.

Trame

Net-like lines of traditional reproductive engraving.

Typogravure

Developed by Italian engineer Michel Manzi, the co-director of art publishing giant Goupil & Cie, the typogravure was a photomechanical process that was based upon block printing. The process is comparable to that of the halftone and allowed for simultaneous printing of text and photography.

Vandyke Process

A photolithographic process used for reproducing maps or plans. It requires the original to have been drawn specifically on translucent paper or on thin Bristol board. A grained sheet of lithographic zinc or aluminum coated with bichromated gelatin is then exposed beneath the original. The plate is then developed with water to leave a stencil of hardened gelatin.  A greasy ink is then applied to the plate and attaches itself to all parts of the metal unprotected by the stencil. The latter is then removed. The plate is treated and used for printing in the lithographic manner.

Verso

A lefthand page of an open book or manuscript (opposed to recto). Also, the back of a leaf page.

Victorian Style

Victorian Style refers to the dominant aesthetic trends throughout the reign of the English monarch, Queen Victoria, which ranged from the years 1837 to 1901. Typically, Victorian style comprised of the overriding sensibility that art should aspire to a higher moral purpose. It was also a time defined by its economic, architectural, urban, and artistic modernization.

Waxed-Paper Process

The waxed paper process is a modification of Talbot’s calotype process. The waxed-paper process was first discovered by Gustave Le Gray in 1848, with the key difference between the original calotype process and the waxed paper process being the manner in which the paper is prepared in relation to exposure. Rather than the calotype process, in which the paper is waxed (in order to increase contrast and speed up the time for each print made from the negative) after exposure and processing, Le Gray implemented the wax saturation of the paper before even the paper is sensitized with photosensitive chemicals. By coating the paper with wax before exposure, the coarseness of the actual fibers of the paper itself is dulled. Also the waxed paper process allowed for sensitized sheets of paper to be stored for long periods of time, thus allowing photographers to prepare their negatives beforehand and increased their ability to travel, reducing exposure times. Photographers of the nineteenth century who used this process included Charles Negre, Henri Le Secq, Roger Fenton, and John Beasley Green. The clarity offered by the wax paper process would be eclipsed by glass plate photography in the 1870s.

Wet Collodion Process

Developed in 1848 and published in 1851 by Frederick Scott Archer, Wet Collodion was one of the most popular photographic processes of the mid to late nineteenth century, ousting both the calotype and daguerreotype processes from favor. The success of wet collodion lies in both its use of glass support for the negative, which resulted in a much sharper and higher resolution image than paper, as well as the reduced exposure time when taking a photograph. The process called for first making collodion, which is done by dissolving gun-cotton (which is cotton soaked in nitric and sulfuric acid and then dried) in ether containing alcohol. The collodion is then iodised by treating it with a saturated solution of potassium iodide in alcohol. This iodised collodion is then poured onto a glass plate and tilted to ensure an even coating. Once an even coating has been obtained the plate is sensitized by bathing it into a silver nitrate solution, which produces light sensitive silver iodide. After one or two minutes the plate is removed from the sensitizing solution and, while it is still wet, placed in the dark slide of a camera and exposed. Immediately after exposure the plate is developed with pyrogallic acid solution or ferrous sulphate solution. The developed plate is fixed either with sodium thiosulphate solution or potassium cyanide solution. The resulting negatives were used to make both albumen and salt paper prints as well as tintypes, oratones and ambrotypes.

Wood Engraving (Woodcut)

A printmaking technique in which an image or pattern (sometimes photographically based) is carved into a block of wood and subsequently used to make reproductive prints and illustrations. The primary difference between a wood engraving and a woodcut is the direction of the wood grain in the original printing block; a wood engraving is carved into the end grain of the wood (perpendicular to the grain of the wood or horizontal to the direction of tree growth) and the image of a woodcut is carved into the plank side of the wood (along the grain of the wood or in the direction of tree growth). Because of this, wood engravings are more precise and are able to convey a wider range of tones. Wood engraving was first developed in England in the late eighteenth century by Thomas Bewick.

Woodbury-gravure

A later adaptation of the Woodburytype which included a transfer process, the Woodbury-gravure process was introduced in 1891. It required a printing a Woodburytype onto temporary support, which was then trimmed and transferred to a final support. The paper that was the temporary support was then peeled away with the addition of a solvent. It was so called Woodbury-gravure because the final result possessed a matte-like surface that recalled a photogravure. However, like the Woodburytype itself, it was also slightly raised in the darkest areas.

Woodburytype

A photomechanical process invented in 1864 by Walter Bentley Woodbury, in which a gelatin relief image is impressed into a lead plate by way of a powerful hydraulic press. This creates a mold relief that is virtually identical to the gelatin relief. Woodburytype prints are then cast within a press by pouring warm pigmented gelatin into the mold and forcing it into contact with a piece of paper. When dry the sheet is removed and the prints are trimmed, as there is always extra gelatin that has squeezed out around the edges, and mounted. The resulting photograph resembles a carbon print, however is a relief image that is thick and slightly raised in the shadows and thin in the highlights, which allowed for a high level of tonal gradation. The popularity of Woodburytypes waned in 1890s after processes such as photogravure and collotype were more suitable to printing photographic illustrations within publications. HCL 141-2

Wove vs Laid vs Plate paper

Laid paper is paper which is manufactured in a gridded wire mold. Because of this, lines are thus imparted upon the papers surface. This way of making paper was popular in the pre-industrial-era, until the process for making wove paper was established in the mid-eighteenth century. Wove paper was produced with a similar mold made of wires, however, the wires used were woven together in a fine wire mesh, not gridded. Because of this, the surface of the paper does not possess any impression of a linear pattern, but rather a more uniform surface. Plate paper is paper produced for printing hand-engraved plates and woodcuts.

Zincography

The process of making zinc printing plates. This can be done through two separate categories of traditional printing: intaglio and planographic.

Zincotypes

Prints produced from engravings or etchings on zinc.