Lithograph by Alfred Mercier, 1892, after a portrait by Harnest aengl, 1834. Senefelder (1771-1834) invented lithography in 1796 while attempting to devise a cheap method for printing his plays. He discovered that Kilheim lime-stone, a highly porous stone, would absorb markings made with a greasy substance. After sketching a design, he washed the surface with water, which soaked into the stone but was repelled by the marked areas. He then applied a printing ink made of a mixture of soap, wax, oil and lampblack which adhered only to the marked areas. By presing a sheet of paper against the stone he gained a clear copy of the design. He called this proces chemical printing, making various modifications and improvents to it, before publishing his findings in 1818.
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