Before-letter proof
Proof before lettering, or avant-lettre. This is a print of an engraving before the engraver has completed the plate by engraving the caption. These proofs are sought after by collectors.
Proofs before lettering refers to those that bear neither signature nor caption. There are also engravings with white letter, grey letter, and black letter.
Fraudulent prints imitating proofs before lettering are obtained by means of a strip of paper placed between the engraved letter and the paper on which it is printed.
