Zincography was a planographic printing

Planographic printing

Planographic printing means printing from a flat surface, as opposed to a raised surface or incised surface . Lithography and offset lithography are planographic processes that utilize the property that water will not mix with oil. The image is applying a to a plate or stone...

 process that used zinc

Zinc

Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 plates. Alois Senefelder

Alois Senefelder

Johann Alois Senefelder was a German actor and playwright who invented the printing technique of lithography in 1796.-Actor, playwright:...

 first mentioned zinc's lithographic

Lithography

Lithography is a method for printing using a stone or a metal plate with a completely smooth surface...

 use as a substitute for Bavaria

Bavaria

Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...

n limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 in his 1801 English

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 patent

Patent

A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

 specifications . In 1834, the Frenchman

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 Breugnot patented a zincographic printing process, producing large maps called géoramas . In 1842, Kaeppelin perfected the process to create a large polychrome

Polychrome

Polychrome is one of the terms used to describe the use of multiple colors in one entity. It has also been defined as "The practice of decorating architectural elements, sculpture, etc., in a variety of colors." Polychromatic light is composed of a number of different wavelengths...

 geologic map .

Process

Zinc plates could be obtained for less expense than fine lithographic limestone, and could be acquired at very large scale. Zinc was coated with a solution containing gallic acid

Gallic acid

Gallic acid is a trihydroxybenzoic acid, a type of phenolic acid, a type of organic acid, also known as 3,4,5-trihydroxybenzoic acid, found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. The chemical formula is C6H23COOH. Gallic acid is found both free and as part of...

 and phosphoric acid

Phosphoric acid

Phosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral acid having the chemical formula H3PO4. Orthophosphoric acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way...

 that caused hygroscopic salts to form on the plate's surface. A printer would then cover the zinc plate with a coating of asphalt

Asphalt

Asphalt or , also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits, it is a substance classed as a pitch...

 varnish, expose it under a drawing and develop it. The zinc affected by the lines of the drawing proof would be coated with hygroscopic salts. Bathing the plate in acetic acid

Acetic acid

Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...

 resulted in the dissolution of the salts, the asphalt varnish protecting the remaining surfaces of the plate. Then the printer would coat the plate with a colored lacquer varnish called fuchsine

Fuchsine

Fuchsine or rosaniline hydrochloride is a magenta dye with chemical formula C20H19N3·HCl. There are other similar chemical formulations of products sold as fuchsine, and several dozen other synonyms of this molecule....

, dried, dipped in benzene

Benzene

Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....

. This would dissolve the varnishes, leaving only the fuchsine varnish in the areas associated with the drawn lines, and hygroscopic salts elsewhere. The printer then wet the plate, the water localizing on the salts. As in lithography

Lithography

Lithography is a method for printing using a stone or a metal plate with a completely smooth surface...

, ink applied to the plate was repelled by the hygroscopic areas, and attracted to the fuchsine

Fuchsine

Fuchsine or rosaniline hydrochloride is a magenta dye with chemical formula C20H19N3·HCl. There are other similar chemical formulations of products sold as fuchsine, and several dozen other synonyms of this molecule....

 areas. Sometimes zincographic printers created printing proofs on specially coated papers .

Variants of the zincographic process included a form of early photographic engraving, photogravure

Photogravure

Photogravure is an intaglio printmaking or photo-mechanical process whereby a copper plate is coated with a light-sensitive gelatin tissue which had been exposed to a film positive, and then etched, resulting in a high quality intaglio print that can reproduce the detail and continuous tones of a...

: zinc was coated with a light-sensitive albumen/chromium

Chromium

Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...

 salt mixture, exposed in contact with a glass negative

Negative (photography)

In photography, a negative may refer to three different things, although they are all related.-A negative:Film for 35 mm cameras comes in long narrow strips of chemical-coated plastic or cellulose acetate. As each image is captured by the camera onto the film strip, the film strip advances so that...

, inked and the albumen removed by washing to create a single proof image. The printer would then transfer the proof design to a zinc plate under a press, and hand-etch the drawing onto the plate with a stylus. The plate was then rubbed with oil, which would not stick to the repellent coating, but adhere in the etched areas. The printer could then ink the plate, and it would remain in the grooves. As in chromolithography

Chromolithography

Chromolithography is a method for making multi-color prints. This type of color printing stemmed from the process of lithography, and it includes all types of lithography that are printed in color. When chromolithography is used to reproduce photographs, the term photochrom is frequently used...

, colors were printed in successive passes of the press, the plates kept in register.

Zincography is frequently confused with modern zinc-plate lithographic printing. It directly influenced the development of photozincography

Photozincography

Photozincography, sometimes referred to as Heliozincography but essentially the same process, known commercially as zinco, is the photographic process developed by Sir Henry James FRS in the mid-nineteenth century....

, an early form of photogravure

Photogravure

Photogravure is an intaglio printmaking or photo-mechanical process whereby a copper plate is coated with a light-sensitive gelatin tissue which had been exposed to a film positive, and then etched, resulting in a high quality intaglio print that can reproduce the detail and continuous tones of a...

.