KEY-PLATE.--Stamps of the same design, when printed in two colours, require two plates for each value; that which prints the design (apart from the value, and sometimes the name of the country), and is common to and used for two or more stamps, is termed the HEAD-PLATE or KEY-PLATE. And _see_ DUTY-PLATE. [Illustration: EXAMPLES OF SOME PHILATELIC TERMS. A sheet of stamps of Gambia, composed of two _Panes_ of sixty stamps each. The single "Crown and CA" watermark as it appears looking from the back of the Gambia sheet illustrated above. The watermark is arranged in panes to coincide with the impressions from the plate.] KNIFE.--This is a technical term for the cutter of the machine which cuts out the (unfolded) envelope blank, and is principally used in connection with the numerous varieties of _shape_ in the United States envelopes, amongst which the same size may show several variations in the flap. LAID.--_See_ PAPER. LAID BÂTONNÉ.--_See_ PAPER. LINE-ENGRAVED.--Is properly applied to a print from a plate engraved in TAILLE DOUCE (which see) but is often applied to the plate itself. LITHOGRAPHED.--Stamps printed from a design laid down on a stone and neither raised nor depressed in the printing lines are denoted by this term. And _see_ PRINTING. LOCALS.--Stamps having a franking power within a definitely restricted area. MANILA.--_See_ PAPER. MATRIX.--A counterpart impression in metal or other material from an original die, and which in its turn is used to produce copies exactly similar to the original die. MILLIMETRE (MM.).--The one-thousandth part of a metre = .03937 inch. MILL-SHEET.--_See_ SHEET. MINT.--A term used to denote that a stamp or envelope, &c., is in exactly the same condition as when issued by the post-office--unused, clean, unmutilated in the slightest degree and with all the original gum undisturbed. MIXED (PERFORATIONS).--In some of the 1901-7 stamps of New Zealand, the original perforation was to some extent defective: such portions of the sheet were patched with strips of paper on the back and re-perforated, usually in a different gauge. MOUNTED.--Usually applied to indicate that a stamp, which has been trimmed close to the design, has had new margins added. And _see_ FAKE. NATIVE-MADE PAPER.--_See_ PAPER. OBLITERATION.--A general term used for any mark employed to cancel a stamp and so render it incapable of further use. OBSOLETE.--Strictly, an obsolete stamp is one which has been withdrawn from circulation and is no longer available for postal use; but the term is often applied simply to old issues, no longer on sale at the post-office. ORIGINAL DIE.--The first engraved piece of metal, from which the printing plates are directly or indirectly produced.