A special stamp showing the fee paid to show receipt of a letter or other postal matter.
Adhesive
Stamp to be affixed to postal matter, as opposed to one embossed or printed directly on an envelope, postal card, or letter sheet.
Aerogramme
An item of postal stationery consisting of a single sheet to be folded into an envelope, sealed, and then sent at a rate less than the airpost letter rate. Postage is usually, but not always, imprinted.
Air post stamps
Stamps specifically issued to carry mail by air transport.
Air post official stamps
Stamps, which utilize air transport, used for carrying mail doing government business.
Air post parcel post stamps
Stamps used for movement of parcel post items via air transport.
Air post postal tax stamps
A postal tax paid when using air post service.
Air post registration stamps
Stamps specifically issued to cover the rate for both registry and air post.
Backstamp
Marking applied to the back of an envelope, showing date and place of arrival.
Barred
Manner of defacing foreign stamps with printed bar-like parallel lines to show they are no longer valid for postage. This has been a government practice of some countries where remainders are sold to dealers at less than face value.
Bicolored
Stamps printed in two colors.
Bilingual
Stamps with their inscription and value printed in two languages. This procedure is or was used in countries with two official languages, i.e., Canada, Belgium, and South Africa.
Bisect
Stamp cut in half so that each part may be used separately to prepay postage. This procedure normally is used in emergency situations when stamps of lower denomination are not available.
Blind Perforation
Perforations that have been only lightly impressed by the perforating pins, leaving the paper intact, but cut. Blind perfs may appear to be imperforate, but some impression is visible on the paper. Blind perfs are minor varieties carrying little, if any, premium over normally perforated copies.
Block
Unsevered unit of four or more stamps, at least two across and two deeps.
Booklet pane
A booklet pane is a configuration of stamps designed to be enclosed in cardboard for ease of storage and use. The panes may be printed from special plates or made from regular sheets of stamps. Panes from booklets issued by many countries contain stamps that have one or more straight edges (without perforations).
Cachet
A design generally applied to the face of an envelope to commemorate an event, such as the first day of issue of a stamp.
Canceled to order (C.T.O.)
Stamps canceled in quantities (without being used as "postage") for sale to collectors.
Cancellation
A mark placed on a stamp to prevent its reuse.
Catalogue
Stamp catalogs are reference works, which list in some logical sequence, as well as describe and usually include some reference as to current market value, stamps of a particularly grouping. Such groupings may be individual countries, geographic regions, specific time periods (by country or region), or a specific topic such as mushrooms pictured on stamps.
Cleaned
Describing a stamp from which the cancellation has been removed, either for reuse as postage or for sale within philately as an unused stamp.
Cliche
A single stereotype of a stamp design.
Commemorative
A stamp issued to honor a particular person, place, or event and which is available for purchase for a specific period of time. Definitive stamps may also honor a person, place, or event, but normally are available for purchase for a much-extended time. In the early days of postage stamps, commemorative stamps were more easily distinguishable from definitive stamps. Today, the line of demarcation is much finer.
Coil stamp
Coil stamps are available in rolls, or coils, for ease of storage and use. Automated application equipment is available to accept such rolls for high-speed stamp application. U.S. coil stamps have perforations only on two parallel sides--horizontal or vertical--while coil stamps of some other countries are fully perforated on all four sides.
Date of issue
The first day a stamp officially is placed on sale is its date of issue.
Definitive
A postage or airmail issue with a much more extended printing run than a commemorative, which normally has a limited quantity issued. Also known as "regular stamps" or "ordinaries."
Demonetized
Stamps declared invalid for postage by government decree.
Design
The printed central part of the stamp within the frame, when there is one. Stamps of the same design may have different inscriptions, country names, denominations, paper, ink color, or perforation measurement.
Die
A small flat piece of soft steel on which the design is recess-engraved in reverse. After completion of the engraving, the die is hardened to withstand subsequent operations. Reproductions are taken from the die to form the plate for printing stamps.
Double impression
A stamp with two distinct, overlapping impressions from the printing plate. This is not to be confused with "Double Transfer."
Double paper
Experimental paper made by pasting two sheets together. Also, the overlap produced when splicing two paper rolls on a rotary press.
Double Transfer
Duplication of all or part of the design of a stamp caused by the changing of registration between the relief and the plate during the rolling of the original entry (transfer). This variety is constant.
Dry printing
A refinement of engraved stamp using thicker, stiffer paper, special inks and greater pressure to force the paper into the recessed plates. on dry-printed stamps, which have whiter paper and high surface sheen, the design stands out sharply.
Duplex cancellation
A cancellation in two parts: the date stamp and the canceling device.
Duty plate
One of two plates used in producing bicolored stamps. The duty plate prints the country name and value, or value only. The head plate, or key plate, prints the remainder of the design.
Early impression
A stamp produced while the plate is still new.
EFO
An acronym, "EFO" is the brief form of "Errors, Freaks, and Oddities." Errors refer to missing colors, inverted colors, and imperforate items, which should be perforated. Freaks and oddities are a more fluid area dealing with color shifts, paper folds that result in interesting ink placements, partial perforations, perforation shifts, ink smears, and others.
Electrotype
A method of producing replicas of a die through the Electro-deposit of copper on a mold made from such a die.
Embossed stamps
Stamps in full or partial relief, with or without color.
Encased postage stamps
Stamps enclosed in special casings for use during coin shortages.
Engraved stamps
Stamps printed from metal plates into which a design is cut or etched.
Engraver's proof
A trial printing from an engraving used to observe how the finished stamp would look.
Entire
A whole stamped envelope, letter sheet, or wrapper used or unused.
Error
A stamps with an unintentional mistake in design, color, perforation, or printing.
Essay
A proposed design, a designer's model, or an incomplete engraving. Its design differs in some way, great or small, from the issued item.
Expertizing
The examination of a philatelic item by an acknowledged expert to determine whether it is genuine, or something less that completely authentic.
Face-different
Of the many ways of differentiating and categorizing postage stamps, "face-different" is the easiest. Face-different refers to a visual difference in the design of a one stamp compared to another. Or, it can be a case of a different color ink used (one stamp in red and another in green, without regard to the design of the stamp). It also may refer to obvious changes in type style used or the placement of type in a stamp design.
Face value
The denomination for which a stamp pays postage.
Facsimile
An imitation of a stamp represented as such.
Fakes
Stamps made to resemble more valuable varieties by altering perforations, "cleaning" cancellations, adding cancellations, and so on.
First day cover
Use of a certain stamp (on cover) or postal stationery item on the first day of sale at a place officially designated for such sale or so postmarked.
First flight cover
An envelope with a cancellation showing the date and starting point of a new air mail route and carried on that route.
Fiscal
A revenue stamp or a postage stamp with revenue cancellation.
Flat plate
Stamps printed on a flat-bed press as opposed to those printed with curved plates on a rotary press.
Frame
The stamp's border, as distinct from its design.
Goldbeater's skin
A tough, transparent paper.
Granite paper
Paper containing visible fibers.
Grid cancellation
A cancellation usually consisting of crisscrossed lines, often within an oval.
