Lithographs are a form of printmaking that involves drawing on a flat stone or metal plate with a special grease pencil. The surface is then treated with a chemical solution that allows ink to adhere only to the drawn areas. When pressed onto paper, the image is transferred, creating a print. This technique was invented in the late 18th century by Alois Senefelder. Lithography is valued for its ability to produce detailed images and is often used for art prints, posters, and illustrations. Artists like Henri de Toulouse-Lautrec and Marc Chagall have famously utilized this method to create vibrant works. The process allows for multiple copies of the same image, making it accessible to a wider audience.