The Traditional Signature
When an artist signs a print, he usually does so on the bottom right-hand side of the print. Since a print is created in "editions" of a certain number of prints, the number of the print and the edition size are noted on the left-hand side.
An artist will sign the print when it is completed to her satisfaction. The signature shows that the artist actually did the work and that she approves it.
Effects on Value
A signed fine art print is more valuable than an unsigned one. A signed print is generally genuine; an unsigned print may be a copy, which isn't worth much.
Unsigned Fine Art Prints
Some artists don't sign their work or simply forget to sign one. Just ensure that the work is legitimate. If it's known that an artist never signed the prints, there is no difference between prints. If they signed some and not others, then a signed print would be more valuable.
Fine Art or Just a Print?
Fine art prints are limited editions, created by the artists. They are not to be confused with reproduction prints sold in vast quantities such as what you might buy in a discount store. In addition, any print edition that numbers in the thousands is not a fine art limited edition.