Block.—An unsevered group of stamps, consisting of at least two horizontal rows of two each.
Bogus.—An expression applied to any stamp not designed for use.
Burelé.—A fine network forming part of design of stamp, or covering the front or back of entire sheet.
Cancelled to order.—Stamps which, though postmarked or otherwise obliterated, have not done postal or fiscal duty.
Centimetre (cm.).—The one-hundredth part of a metre = .3937 inch.
Chalky, or chalk-surfaced.—Before being used for printing, paper sometimes has its surface coated with a preparation largely composed of chalk or similar substance: this renders the print liable to rub off if wetted; and, in combination with a doubly-fugitive ink, renders fraudulent cleaning practically impossible.
Cliché.—The ultimate production from the die, and of a number of which the printing plate is composed.
Colour trials.—Impressions taken in various colours from a plate, so that a selection may be made.
Comb machine.—A variety of perforating machine, which produces, at each descent of the needles, a line of holes along a horizontal (or vertical) row of stamps, and a short line of holes down the two sides (or top and bottom) of each stamp in that horizontal (or vertical) row. And see Perforation.