Lithograph is one of the most misunderstood and misrepresented words in fine art today. Inaccurate usage of the word in advertisements and articles has blurred its real meaning and produced considerable confusion among buyers and even dealers. Even some galleries that sell prints have misrepresented lithographs or have labeled reproductions as stone lithographs. If you don't know the difference between an original stone lithograph and a lithographic reproduction, you are not alone.
Many graphic buyers are unaware of the difference until it's pointed out.
After chemical treatment with a gum arabic and nitric acid, the stone is wetted and an ink charged roller is passed over the surface of the stone. Ink is accepted by the grease image and simultaneously repelled by the blank areas of the stone, which retain the water. A print is obtained by placing a sheet of paper on the inked stone, which has been mounted onto the bed of the lithographic press and then running the stone and paper under the scrapping pressure of the press. For a multi-colored lithograph, the artist draws and prepares a separate stone for each color used. One sheet of paper must be printed from four different stones to create the desired effect of a four color lithograph.