Oil pressure (printing technology)
The oil pressure (also bromoil ) is a precious printing method for producing a printing form by photographic exposure, developed in 1866 by Emil Mariot (1825-1891). It is based on a colloid layer treated on the surface with fat paint . The manufacturing principle is similar to coal pressure . The color pigments are now not stored in the colloid layer, but are subsequently pushed onto the colloid layer. One makes use of the repulsion of fat and water. The tanned parts of the gelatine absorb little or no water, but more fat color. Because the image layer in these photographs consists of color containing pigments, the images are very durable and do not change like silver bromide prints, for example.
The Ölumdruck (also Bromölumdruck or Bromöl transfer pressure ) is a technique for producing a printing form by a photographic exposure, and similar, because it is made on the rejection of fat-containing and water-containing layers, the lithographic process . If you reprint such a print on new paper, the photographic origin can no longer be easily recognized.
The fat color image obtained with the oil print is then transferred to normal paper in the copper printing press. As with collotype printing, which is related to the process, the process can often be repeated. With several overprints one on top of the other, a greater wealth of tonal values is achieved; multi-colored prints are also possible. Oil transfer was invented by William de Wiveleslie Abney in 1873 and further developed by Robert Demachy in 1911 .
literature
- Wolfgang Autenrieth: New and old techniques of etching and fine printing. From witch's meal and dragon's blood to the photopolymer layer. Tips, tricks, instructions and recipes from five centuries - An alchemistic workshop book 6th edition, Krauchenwies 2010, ISBN 978-3-00-035619-3 ( table of contents , (→ excerpts online) )
- Josef Maria Eder : Detailed handbook of photography. Volume 4, Part 2: The pigment process. Oil, bromine oil and rubber printing, blueprint and dusting processes with chromates, pinatype, kodachrome, hydrotype, copying processes with coloring organic compounds, diazotype processes, images with tanning and chromogenic developers and artificial resins. 4th, completely revised and enlarged edition. Knapp, Halle (Saale) 1926 (reprint. Lindemans, Stuttgart 1990, ISBN 3-928126-09-1 ).
Web links
- Extensive link collection on etching techniques and fine printing processes
- Etching online workshop book on the techniques of etching and the fine printing process