Planographic printing means printing from a flat surface, as opposed to a raised surface (as with
relief printing) or incised surface (as with
intaglio printing).
Lithography and
offset lithography are planographic processes that rely on the property that water will not mix with oil. The image is created by applying a (greasy substance) to a plate or stone. (The term lithography comes from
litho, for
stone, and -
graph to draw.) Certain parts of the semi-absorbent surface being printed on can be made receptive to ink while others (the blank parts) reject it.