Lithography is a printing process that involves creating images on a flat surface, typically using a stone or metal plate. The technique relies on the principle that oil and water do not mix. An image is drawn on the surface with a greasy substance, and then the plate is treated with a chemical solution that allows ink to adhere only to the greasy areas, producing a printed image. This method was invented in the late 18th century by Alois Senefelder, and it has since evolved into various forms, including offset lithography, which is widely used in commercial printing. Lithography is valued for its ability to produce high-quality images and is commonly used for art prints, posters, and packaging.