Using a lithograph, a printer can make many original prints of one image. An artist draws a picture onto a metal plate or stone using a pencil, crayon or paint. This picture is pulled onto good quality paper by a master printer or by the artist themselves. The more involved the artist was in the creation of the print, the more expensive the print will be. Offset copies are not created by the artist and do not have their stamp of approval.
Consult with an artist who has used or currently uses lithographs. Learn how modern lithographs are made. Look at examples of originals and reproductions through your friend. The more times that you compare originals to lithographs, the easier it will become for you to identify which is which.
Check the picture for a signature. Every lithograph will have a unique pencil signature on its bottom right corner, while an original art piece will have a signature in paint or other material. This pencil usually signifies that that print was produced and approved by the artist. Sometimes the artist will also put her seal on the artwork.
Look at the edition and series numbers. You can find these numbers under the signature and they will look like a fraction. The top number tells us the print's place in creation. The bottom number tells us how many prints were created. You can then contact the artist or a dealer and inquire about the particular art that you have.
Inspect the lithograph under a magnifying glass. Original artwork will have raised paint blotches. Authorised lithographs will have solid and rich colour. Additionally, their ink will be smooth. Offset lithograph prints will be made of many imprecise and tiny dots.
Consider the paper. Original lithographs will be printed on heavyweight, acid-free paper that may have been handmade. They will show no rims of ink, metal plate markings or raised ink surfaces. Original lithograph prints will come with a certificate of authenticity that explains the print's history.
To be sure of the print's authenticity, only buy fine art from reputable art galleries, houses or auctions.