Double-print.—Strictly applicable to two similar impressions, more or less coincident, on the same piece of paper; though often, but erroneously, applied to instances where the paper, not being firmly held, has touched the plate, so receiving a partial impression, and then, resuming its correct position, has been properly printed.
Duty-plate.—Many modern stamps are printed from two plates, one being the same (key-plate, which see) for all the values, but the other differing for each denomination: this latter is the duty-plate.
Electro.—A reproduction of the original die, made by means of a galvanic battery from a secondary die. See Matrix.
Embossed.—Stamps produced from a die, or reproductions thereof, on which the design is cut to varying depths, are necessarily in relief, i.e., embossed. And see Printing.
Engraved.—The term is often used to denote stamps printed direct from a plate, on which the lines of the design are cut into the metal. And see Printing.
Entires.—This expression includes not only postal stationery (which see), but when used in describing an adhesive stamp, as being "on entire," implies that the stamp is on the envelope or letter as when posted.
Envelope stamp.—A stamp belonging to, and printed on, an envelope.
Error.—An incorrect stamp—either in design, colour, paper, &c.—which has been issued for use.
Essay.—A rejected design for a stamp; in the French sense also applied to proofs of accepted designs.