T: Abbreviation for the French “Taxe.” Handstamped on a stamp, the T indicates the stamp’s use as a postage due. Handstamped on a cover, it indicates that postage due has been charged. Several countries have used regular stamps with a perforated initial T as postage dues.
Tagging: Phosphor material on stamps used to activate automatic mail-handling equipment. This may be lines, bars, letters, part of the design area or the entire stamp surface. The tagging may also permeate the stamp paper. Some stamps are issued both with and without tagging. Catalogs describe them as tagged or untagged.
Teeth: The protruding points along the outer edge of a perforated postage stamp when it has been removed from the pane.
Telegraph stamp: Label used for the prepayment of telegraph fees. Telegraph stamps resemble postage stamps.
Tete-beche: A French idiom with the philatelic meaning of a pair stamps in which one is upside- down in relation to the other.
Thematic: A collection of stamps or covers relating to a specific topic. The topic is expanded by careful inquiry and is presented as a logical story.
Tied: A stamp is said to be tied to a cover when the cancel extends over both the stamp and the envelope paper. Stamps can also be tied by the aging of the mucilage or glue that holds them to the paper.
Tong: Tweezerlike tool with rounded, polished tips, used to handle stamps. Tongs prevent stamps from being soiled by dirt, oil or perspiration.
Topical: 1) Stamp or cover showing a given subject. Examples are flowers, art, birds, elephants or the Statue of Liberty. 2) The collection of stamps by the topic depicted on them, rather than by country of origin.
Traffic Light: Most of the multicoloured stamp sheets are printed with colour marks on the margins of the sheet. This enables the printer to know whether any colour is missing, in printing. Such corner stamps with colour symbols are known as traffic light stamps.
Transit mark: A postal marking applied by a post office between the originating and receiving post offices. It can be on the front or back of a cover, card or wrapper.
Triptych: A se-tenant strip of three related stamps forming one overall design.
Type: A basic design of a stamp or a set. Catalogs use type numbers or letters to save space. Catalogs show a typical design of one type rather than every stamp with that design or a similar design.