Invented in Germany in 1798, lithography was the first fundamentally new printing technology since the invention of relief printing in the 15th century. Coming into common use in the middle of the 19th century, it opened a new world for natural history illustrators who could draw directly on the stone themselves and eliminate the need for a skilled artisan. The technique was based on the principle of the resistance of grease to water. The image was drawn with greasy ink or crayons on a specially prepared slab of limestone. The stone was moistened with water which the stone accepts in areas not covered by the crayon. An oily ink, applied with a roller, adheres only to the drawing and is repelled by the wet parts of the stone. A print was then made by pressing paper against the inked drawing through a lithographic press.