Proof
Also called: proof, proof of first impression
A proof is a low volume printed version of the desired printed material. This proof can be used to check whether a digital design also looks as desired physically printed. This allows the final product to be checked for any errors and imperfections without having to destroy an entire print run in the event of such errors.
The proof can be made once the design has been approved and made ready for printing. Usually it is one or a few copies, intended only for control purposes. Nowadays, many printers work with "digital proofs," in which the supplied file is converted to a PDF file whose layout matches the printed version of the document or design.
When a trial issue of a new magazine is made prior to its official launch, it is called a zero issue. Such a trial edition, like a proof, can be used to make adjustments to the final format.