What is Lithography?

Lithography, which means literally “Stone writing”, is one of four distinct printing techniques.  It is the only technique in which the image is neither raised above the rest of the surface (wood engraving, wood- and lino-cutting), nor cut into it (etching and metal engraving), nor in the form of a stencil (screenprinting), but differentiated from it by chemical means.

It was discovered in the late 1790’s by Alois Senefelder in the Bavarian town of Solnhofen, and although initially used for commercial printing of musical scores, was quickly appreciated by artists for its major characteristic: direct and faithful reproduction of the artist’s pen, crayon and brush marks.  Originally it was discovered to work on limestone blocks, but later grained zinc and aluminium plates were also found to be receptive to the process.  With the application of photographic technology, then the development of the offset press and, most recently, types of plastic printing plates, the principles of lithography are still at the heart of modern commercial printing while offering artists diverse avenues to explore.  It is well known to today’s public through the prints of artists such as Daumier, Toulouse-Lautrec, Bonnard, Picasso and Hockney. 

Lithography depends on the principle that oil and water do not mix.  An image is created on the flat surface of a prepared limestone block, which is receptive to the greasy drawing materials: crayons and lithographic drawing ink.  Certain types of Jurassic limestone, usually from the region of Germany where Senefelder originally discovered the process and between about 6 to 12 cm in thickness, are ground smooth on their upper surface with fine grit and water.  This prepares the stone to receive the grease, which is present in the drawing materials.  The image is drawn or painted on the sensitive surface of the stone in much the same way as on paper or canvas.

When the drawing is dry the stone is coated with an acidic solution of gum arabic, which prevents the adherence of further grease on the areas which are not to be printed.  The drawing material is cleaned off with turpentine through the gum arabic and the stone is washed with water, dissolving some, but not all, of the gum.

The stone is kept damp.  The parts, which have been drawn on, being greasy, repel the water; the rest, helped by the residue of gum arabic, retain it.  Oil-based ink is rolled onto the stone. The greasy parts, i.e. the drawing, retain the ink.  Paper is placed on the stone and together they are pulled through the press and the ink is transferred to the paper.

Coloured lithographs are produced by taking impressions from several stones in succession, each adding a different colour to selected parts of the print.

You can watch a video introduction to lithography on the Oaks Editions Lithography Studio YouTube channel.