A preprint autograph is essentially a fake. It is a copy or photographic reproduction of an original. A preprint autograph generally has no monetary value. If it does have any value, it is much less than what an original is worth.
Many stars send out preprint autographs to their fans because of fatigue or lack of time. Major stars such as Johnny Depp may find that the demand is just too high. Fans looking for original autographs must do some research before they buy. To start, here is a short list of celebrities believed to only send out preprint autographs: Henry Winkler, Jennifer Garner, Drew Barrymore, Halle Berry, Andy Garcia, Jennifer Aniston and Jim Carrey.