a medium is a

Lithograph is a type of print, not a medium. Printing is a medium, painting is a medium, lithography is a medium, but a lithograph is a product, like A painting is a product. Lithos are usually drawn with grease pencils of some sort in a mirror image of the subject you want on a smooth stone or metal plate, then water-based inks are applied, one color to each pass of the print.