Stone Lithography
Invented by Aloys Senefelder in the late 18th century, lithography (derived from the Greek words for "stone" and "writing") is a printmaking technique typically utilizing limestone plates. The artist uses a greasy material to draw an image on the stone surface. The surface is then treated chemically (etched) so that only the greasy image will accept the printing ink. A press is then used to print copies onto the paper (the edition). Since there is a limited supply of stones, after the completion of the edition they are resurfaced and reused. The edition is, therefore, truely limited.
For further information see "The Tamarind Book of Lithography" published by Harry N. Abrams, Inc., Publishers, New York (1971).