Lithography, which was the first new discovery in printing after the relief, is a mechanical process. The printing and the non printing areas are at the same levels in the plate and it is completely basen on water repelling the oil. Chemical processes create the image. Alois Senefelder invented litography. He was an actor and a playwright and when printing his play was a problem, he fell into debt and needed money. Therefore, he experimented with new techniques using greasy and acid resistant ink. He then discovered that he could print from the flat surface of a stone. Senfelder also made litography as a potential for a medium of art. This is because artist could draw very easily on the surface of the stone with pens. Specimens of Polyautography was published soon after. It was a portfolio of artist lithographs.
Here is an example from the book:
Of course number of works from much later years show how lithography took a turn and how artists used this technique.
Picasso, Woman in an Armchair No:1 (1948)
Lolita Film Poster by Roger Soubie