The image is drawn with a grease crayon or pencil, or painted with tusche, on a flat stone such as limestone. Alternatively, a metal plate (aluminum or zinc) can also be used instead of a stone plate. The surface is then chemically treated and dampened with water so that the image areas repel water and attract oil-based ink, while the non-image areas attract water and repel ink.
Once the plate is inked, the image is transferred to a damp paper with a lithographic press. A lithograph is monochrome by default - to create a lithograph with multiple colors, multiple different plates must be created and the paper must go through the press several times.
Lithography was invented in 1798 in Germany by Alois Senefelder. It reached its highest popularity in the 19th century. Instead of drawing the image on the plate with a grease crayon, it can also be produced by photochemical and transfer processes.