Occasionally you may come across a print that has the letters “AP” instead of an edition number. AP means that copy is an artist's proof - that is to say a proof printed before the numbered copies of the edition. AP copies are often retained by the artist to give to friends and family. They are usually signed, and will often have a number to indicate how many Artists’ Proofs were created. Some collectors prefer to obtain artist's proof copies as these can be more interesting and are rare in comparison to the numbered copies, and if they are inscribed with a message or dedicated by the artist, they can be very collectable and as such more expensive.