Lithography - Printing process that
makes use of the immiscibility  
(cannot undergo mixing or blending)
of grease and water. Aloys
Senefelder of Prague (1771 – 1834)
exploited the properties of a stone
with a calcium carbonate base and a
fine, porous surface, and perfected
his printing process in 1798. In
Senefelder's process, the stone, with
a design drawn on it with crayon or
greasy ink, was wetted with water;
after various etching and protecting
steps, it was brushed with oily ink; it
retained the ink only on the design.
This inked surface was then printed
— either directly on paper, by a
special press (as in most fine-art
printmaking), or onto a rubber
cylinder and then onto paper (as in
commercial printing). The method of
preparing stones for hand printing,
still the lithographic method preferred
by artists, has hardly changed.
Commercial lithographic printing on a
modern rotary offset printing press
can produce high-quality, finely
detailed impressions