Invented in the late 18th century, Lithography relies on the principle that water and oil or grease don’t mix. Originally, a drawing was made with a wax crayon or greasy liquid on a smooth limestone. I use light sensitive metal plates and the initial drawing is made on a transparent material. Each colour is printed from a separate plate which is alternately sponged and then rolled with think layers of oil-based ink. This process is repeated several times to allow sufficient colour to build up then dry smooth Somerset paper is placed on top of the plate, using registration marks and printed on a lithographic plate printing press.