Traditionally, the image to be printed was drawn with a greasy substance, such as oil, fat, or wax onto the surface of a smooth and flat limestone plate. The stone was then treated with a mixture of weak acid and gum arabic ("etch") that made the parts of the stone's surface that were not protected by the grease more hydrophilic (water attracting). For printing, the stone was first moistened. The water adhered only to the gum-treated parts, making them even more oil-repellant. An oil-based ink was then applied, and would stick only to the original drawing. The ink would finally be transferred to a blank sheet of paper, producing a printed page. This traditional technique is still used for fine art printmaking.Peterdi, Gabor F. (2021): "Lithography" section of "Printmaking" article. Encyclopedia Britannica online. Accessed 23 November 2021.
Traditionally, the image to be printed was drawn with a greasy substance, such as oil, fat, or wax onto the surface of a smooth and flat limestone plate. The stone was then treated with a mixture of weak acid and gum arabic ("etch") that made the parts of the stone's surface that were not protected by the grease more hydrophilic (water attracting). For printing, the stone was first moistened. The water adhered only to the gum-treated parts, making them even more oil-repellant. An oil-based ink was then applied, and would stick only to the original drawing. The ink would finally be transferred to a blank sheet of paper, producing a printed page. This traditional technique is still used for fine art printmaking.Peterdi, Gabor F. (2021): "Lithography" section of "Printmaking" article. Encyclopedia Britannica online. Accessed 23 November 2021.