There are two main processes of early print making: relief and intaglio. Lithography was invented in the 18th century as a cheaper process of mass printing. In relief processes the negative is either cut or etched away, leaving the design, or positive image, standing in relief, and that is the printing surface. In intaglio printing the opposite is the case; the design is cut or etched away. Printing ink is applied to the surface then wiped clean, leaving ink in the incisions or grooves. Enormous pressure is then required to press the paper onto the printing surface. In lithography the image is applied to a printing surface, usually a stone surface, with fat, oil or wax.