PROOF, in brandy and other spirituous liquors, is a little white lather which appears on the top of the liquor when poured into a glass. This lather, as it diminishes, forms itself into a circle called by the French the épaulet, and by the English the bead or bubble.
PROOFS of Prints, were anciently a few impressions taken off in the course of an engraver's process. He proved a plate in different states, that he might ascertain how far his labours had been successful, and when they were complete. The excellence of such early impressions, worked with care, and under the artist's eye, occasioning them to be greedily sought after, and liberally paid for, it has been customary among our modern printellers to take off a number of them, amounting, perhaps to hundreds, from every plate of considerable value; and yet their want of rareness has by no means abated their price. On retouching a plate, it has been also usual, among the same conscientious fraternity, to cover the inscription, which was immediately added after the first proofs were obtained, with slips of paper, that a number of secondary proofs might also be created.