Lithography - preparing the stone
1. A limestone is ground down by placing it onto a graining sink and washing it with water. It is ground by using either another stone or a levigator with an abrasive grit to create a smooth, even surface onto which a new image is created.
2. The artist draws directly onto the limestone slab using a grease crayon or any variety of grease-based materials.
3. The drawing is then etched by applying various mixtures of gum arabic and nitric acid that correspond to the amount of grease applied in the image areas. The mixtures chemically alter the surface of the stone, creating sensitized image areas that will consistently accept oil-based printing ink and desensitized non-image areas that will consistently reject ink.
4. A protective film of gum arabic is then buffed into the stone and allowed to dry.