lithography research

Lithography uses simple chemical processes to create an image. For instance, the positive part of an image is a hydrophobic, or "water hating" substance, while the negative image would behydrophilic or "water loving". Thus, when the plate is introduced to a compatible printing ink and water mixture, the ink will adhere to the positive image and the water will clean the negative image. This allows a flat print plate to be used, enabling much longer and more detailed print runs than the older physical methods of printing (e.g., intaglio printing, Letterpress printing).

Lithography was invented by Alois Senefelder in Bohemia in 1796. In the early days of lithography, a smooth piece of limestone was used (hence the name "lithography"—"lithos" (λιθος) is the ancient Greek word for stone). After the oil-based image was put on the surface, a solution of gum arabic in water was applied, the gum sticking only to the non-oily surface. During printing, water adhered to the gum arabic surfaces and avoided the oily parts, while the oily ink used for printing did the opposite.

Lithographic crayons and pencils are manufactured in a range from very soft and greasy through to being very hard and dry. As a consequence mark-making is potentially limitless and they can be used to great effect to develop drawings of varying character. Considerable detail and full range of tone from the subtlest grey to the densest black can be achieved. Rubbing crayon which is commonly applied to the surface of stone using rag may also achieve soft smudgy atmospheric effects similar to that found in charcoal drawing and a good example of its use can be seen in the print Quotidian by Donald Furst.

The liquid drawing ink known as tusche is favoured by many lithographers as it will dry and reticulate on the surface of the stone in the most astonishing manner, creating exaggerated web-like patterning on the surface of the stone.



Here is a very good tutorial on how to create a lithographic print.
http://www.youtube.com/watch?v=JHw5_1Hopsc

research: http://en.wikipedia.org/wiki/Lithography
http://www.spgw.co.uk/characteristics4.html

artists:
rex ray: http://www.globalgallery.com/search.php?af=rex+ray

Sarah June Change: http://www.globalgallery.com/enlarge/25031/

Robert Rauschenberg: http://www.globalgallery.com/enlarge/89764/