When a set of identical impressions is made from an individual plate or group of plates it is called an edition. Editions can be made by the artist, either working alone or in conjunction with a master printer. Proofs are any impression pulled before the official edition. A “Bon à Tirer ” (abbreviated as B.A.T.and means ready to pull) is the final proof approved by the artist and is the proof to which the entire edition is matched. The edition number does not include proofs, but only the total number of prints in the numbered edition.
While the numbering of individual impressions can be found as early as the late nineteenth century, it did not become standard practice until the mid-1960s. Before it was possible to preserve the surface of a plate for longer print runs, the order in which the edition was printed was important. In todays practice the numbering sequence no longer reflects the order of printing, although the work is still done by hand, master printers are highly skilled at producing identical impressions for an edition. Numbering is now transcribed as a fraction with the top number signifying the number of that particular print and the bottom number representing the total number of prints in the edition.
Signatures tell a viewer a lot about the authenticity and dating of a print. The very earliest prints did not have signatures at all, although by the late fifteenth century many artists indicated their authorship of a print by incorporating a signature or monogram into the matrix design. This kind of composition is called “signed in the plate” or a “plate signature.” While some prints were pencil signed as early as the late eighteenth century, the practice of signing one's work in pencil or ink did not really become common practice until the 1880s. Today, it is customary for original prints to be signed. When a print is described simply as “signed” it should mean that it is signed in pencil, ink or crayon. A plate signature or a stamped signature should be described as such.