Ask the seller for the name of the artist. If the seller cannot identify the artist for a painting or photograph, it is probably a forgery.
Go with your gut when it comes to price. Any print price that seems too good to be true probably is.
Ask where and how the seller obtained the print. If your seller cannot explain how he came across this valuable item, you may want to find another, more reputable dealer.
Compare the print to other works by the artist. If the work looks substandard or is out of the artist’s traditional style, avoid the purchase.
Check the gallery for replicas of the same print. If a gallery offers more than one of the same painting, you can bet they are not originals.
Work directly with artists whenever possible. Buying from the artist or her direct representative ensures your prints are legitimate.