Zincography is a photomechanical process designed to produce typographic cliches and to print halftone images from them using letterpress printing . The technology got its name due to the fact that zinc , which has good print run resistance, was most often used as a material for clichés. Due to the relative simplicity, zincography was widely used in newspaper printing , which allows low image quality.
Content
Technology Description
The etching of pen and pencil drawings on zinc, used instead of lithographic stone , was tested in 1804 by W. Eberhard, he called the method of hemiography. Only by 1850, for the first time, successful results were achieved in the manufacture of zinc cliches with embossed images convenient for printing on an ordinary printing press (panicography, or housing). However, in this way it was possible to print only contour or line art, without a continuous shadowing of shadows and halftones. In 1862, the one used to this day appeared [ when? ] photocincography, that is, photographing a picture on a properly prepared zinc plate and then etching the resulting image. After improving this method and combining it with autotype, zincography became suitable for making clichés from original originals and became an industrial method in the 1880s. Due to the cheapness and ease of printing, this technology has become very widespread.
Zincography is unsuitable for the direct reproduction of halftones, so photographs before making cliches are rasterized with a dot or linear raster using the autotype method. To do this, with the help of a large-format camera , the original is reproduced through the raster, which is closely pressed to the emulsion. The resulting raster negative is printed in a contact manner on a zinc plate coated with a photosensitive layer. As a photosensitive layer, a mixture of dichromates with albumin can be used, which becomes insoluble under the influence of light. After exposure using an arc lamp, the plate is covered with paint and appears in cold water [1] . In this case, the paint is washed off from unexposed areas, which are then etched in an acid bath. For higher acid resistance, the paint layer is further strengthened by heating (enameling) or asphalt powder. As a result, in unexposed areas, the zinc layer is removed to the desired depth, forming white space elements. For the printing of color illustrations, several single-color cliches are used, usually used: yellow, purple, blue and black inks. For full color printing by zincography, copper clichés are often used instead of zinc because of their higher stability.
See also
- Phototype
- Woodcut
- Gillo, Firmen
Notes
- ↑ Photomechanical processes, 1932 , p. 178.
Literature
- Yu.K. Laubert. Photomechanical processes / V. Popov. - M .: "Gizlegprom", 1932. - S. 165-189. - 416 p. - 7000 copies.
- Zincography // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.
Links
- Zincography - an article from the Great Soviet Encyclopedia .
- Engraving in printing. Historical essays.
- Zincography - the basics of printing production. A.I. Geodakov // M. Art of 1962. 310s.