Picture: Schematic drawing high pressure
Relief printing is a printing process in which the protruding areas of the printing block (printing plate) are inked. By pressing or rubbing a paper onto the printing block, the print is then produced.
The most important processes of high pressure:
-Woodcut: woodblock printing
-Linocut: Printing block made of linoleum
Picture: Ferdinand Arnold, Untitled 4, 2014. linocut
Picture: Corsin Fontana, Untitled 1, 2014. woodcut
Picture: Schematic drawing gravure printing
In gravure printing, the motif is applied to a printing plate by means of depressions (scored, etched, scraped). These depressions are filled with printing ink. The ink is absorbed by the moistened paper which is pressed onto this plate.
A simple recognition feature of gravure printing is the visible impression of the printing plate. The printing plate can be made of copper, zinc or glass.
The most important processes of gravure printing:
If the printing plate is processed directly by hand, the following techniques can be distinguished:
-Drypoint technique: drawing scored with steel needle
-Copper engraving: drawing engraved with graver
-Mezzotint: different shades by roughening and polishing
In etching techniques, it is not the plate itself that is processed, but an acid-resistant layer that is applied to the plate. In the subsequent acid bath, the etching liquid attacks the metal wherever the protective layer is damaged. The paint will stick to these areas during the dyeing process.
There are different ways of processing the plate before the acid bath. Among the most important etching techniques:
-Aquatint: different shades by covering surfaces in an acid bath
-Blasting method: drawing/painting is done with a sugar ink directly on the printing plate, after which the whole plate is covered with an etch-resistant layer. In the following water bath the sugar blasts away the overlying layer
-Heliogravure (photogravure): The starting point for heliogravure is a photosensitive paper coated with dyed gelatine. This is exposed to a positive film under UV light. The UV light hardens the gelatine and the unexposed areas are washed out. The motif thus remains on the paper as a gelatine relief. The gelatine relief is applied to the copper plate, which has been treated in the same way as in the aquatint process. In the etching bath the acid eats into the copper plate, depending on the thickness of the gelatine. The print almost reaches the reproduction accuracy of a photograph
-Hyalography: Pressure plate made of glass
-Brush etching: the acid is applied directly to an iron or aluminium plate with a glass brush
-Etching: drawing scribed with etching needle
-Soft ground etching/Vernis mou: drawn through a paper to which the soft varnish sticks to the printing areas
Picture: Cécile Wick, Untitled 1, 2015. heliogravure
Picture: Marcel Gähler, Untitled 1, 2017. mezzotint
Picture: Schematic drawing flat printing
In planographic printing, the printing areas are on the same plane as the non-printing areas. Planographic printing is based on the principle of mutual repulsion of water and greasy ink.
The most important methods of planographic printing:
-Lithography: In lithography, ink or chalk containing grease is used to draw directly onto the stone slab. The plate is moistened and then coloured, whereby the ink only adheres to the greasy areas. The ink is then pressed onto the paper under strong pressure of the litho press
-Offset printing: Offset printing works on the same principle, whereby the stone plate is replaced by an aluminium cylinder. The ink is transferred to the paper in the rotary press via a rubber blanket.
Picture: Sabian Baumann, "Sky, Eye, Rocaille", 2016. Lithography
Picture: Schematic drawing screen printing
In screen printing, also called serigraphy, stencils are used on a stretched screen made of nylon or wire to cover what is not to be printed. The stencils can be made by hand or photomechanically. The ink is then pressed through the screen onto the paper with a squeegee.
Picture: Beat Zoderer, "DODES'KA-DEN I", 2016. silkscreen
-Prints, Handbook of artistic printing techniques, Karin Althaus, Scheidegger & Spiess, 2008
-Prints: History and Technical Terms, Ernst Rebel, Reclam Non-fiction, 2009