Invented by Bavarian copperplate engraver Alois Senenfelder in 1796, lithography was the first planographic, or flat surface, printing process. Based on the mutual repulsion of grease and water, an image was drawn in reverse with greasy ink on a damp, porous stone, most often limestone. Printing ink adhered to the image, not to the non-greasy wet area. The stone then passed through a press transferring a positive image onto paper.
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