What is a lithograph ?
The word comes from the Greek lithos (stone) et graphein (write).
Lithography was invented by Aloys Senefelder in 1796 in Germany. This is a printing technique that allows the creation and reproduction of drawings on paper previously executed by a designer, with a grease pencil, on a lithographic stone. It is a noble art technique to realize proofs of which edition depends on the complexity of the design and quality of support.
Each lithographic print is produced on a special paper, the Arches paper (textile fiber that provides excellent aging work well above the oil painting) or vellum, and is almost considered as an original print.
How is achieved a lithograph?
On the sanded stone, the designer draws directly using a pencil or greasy ink. Once the composition is over, an aqueous solution of gum arabic, weakly acidified is applied to the stone. It acts on the limestone wherever it is not protected by the ink or pencil.
After wetting the stone, an ink roller which deposits the ink on the raised portion of the stone (the designed part) is applied. For the color lithography, a single drawing on the stone per color is required: a lithograph can sometimes need dozens of drawings, color by color! It is often the longest stage.
Printing ink is then rolled over the surface and the stone and paper are run through a press which applies even pressure over the surface, transferring the ink to the paper and off the stone. Generally between 100 and 500 can be printed by this technique. Beyond, the support is no longer usable and the stone is destroyed.
Is there a difference between a lithograph and a reproduction?
A very big difference, since the lithograph is hand printed, in a limited number of copies, while the reproduction is obtained by a photomechanical process for thousands of copies. If we make the comparison with fashion, then the lithograph is an haute couture model, while the reproduction is making. This explains the difference in quality and price.
The value of a lithograph depends on the artistic quality of the work and the prestige of the author more than the support, "stone", used for manufacturing. Instead of stones, heavy and cumbersome, zinc plates can be used, properly prepared. This modern medium which is a thin metal plate coated with calcium carbonate is as valid as the stone is more convenient and certainly less unwieldy.