Lithography, invented by Alois Senefelder of Germany at the end of the 18th Century, is a planographic, or flat surface, printing technique. The term "lithography" combines Greek and Latin words to mean "writing on stone." While commercial lithographers utilize zinc or aluminum sheets for the printing process, artists prefer to use the surface embraced by Senefelder--limestone--which provides flexibility and tonality not found with the metal sheets.
History
Alois Senefelder, a writer frustrated by his inability to line up a publisher for his works, acquired blocks of limestone in an attempt to make his own etchings of his writings for printing purposes. When he inadvertently wrote on the stone with a grease pencil and saw that the words attracted ink and repelled water, he discovered a whole new, and easier, way to print on paper. He called his discovery "chemical printing," but as the technique grew in popularity among artists working in Paris in the early 1800s, the term "lithography" became more commonly used.
Technique
Lithography is based upon the repulsion of water to grease. To create a lithograph, use water-resistant drawing tools, including litho chalks (also known as litho crayons), a litho pen or even a brush to apply melted, greasy litho ink, to draw or paint on stones (usually limestone) or sheets of metal or plastic. Then use special chemicals--French chalk, nitric acid, gum arabic and turpentine--to process the stone plate, so the non-sketched areas will attract water and repel the greasy ink while the drawing itself holds onto the ink. After properly preparing the stone, cover it with ink and place a piece of paper over it. Then run it through a press to print the drawing. Each color application requires a separate stone or sheet.
Benefits
Limestone was the first material used to create lithographs, and for many fine artists, it remains the preferred material. "Stone is a lot more versatile than metal plates," said Bill Lagattuta, shop manager of the Tamarind Institute, a fine-art lithography center in Albuquerque, N.M., in an interview with the PBS series, Antiques Roadshow. Limestone used for lithography is porous with a flat, smoothed surface. According to Lagattuta, limestone has a greater tonal range than metal or plastic sheets and provides artists with the ability to scratch into a picture to create texture. As far as which type of limestone to use, Lagattuta favors the same Bavarian quarry that supplied Senefelder with his supply centuries ago. "The Bavarian limestone just doesn't have as many fossils or other imperfections," Lagattuta said.
Drawbacks
While artists have embraced limestone for its versatility and rich tonality, the stones are heavy, cumbersome and can crack under too much pressure from a press. They are also expensive; according to Lagattuta, a 24-by-30 inch sheet of limestone can cost several thousand dollars to purchase and ship. Proponents of limestone cite that the material can be regrained, or ground down to obtain a fresh surface--a clean slate--for new drawings. Many find the regraining process arduous, but the cost of a new stone makes it worth their while. Artists also can purchase used stones.
Stone Substitutes
Metal plates--usually aluminum or zinc--can perform the same basic function as a litho stone, but without the great versatility and tonality. Plates are far less expensive than stone, readily available and easier to transport. Additionally, they can be sent away for regraining to be used again. While limestone remains unsurpassed as the artists' preferred material for lithography, metal plates make the medium more affordable for all.
