A postage stamp is evidence of pre-paying a fee for postal services. It is usually a small paper rectangle which is attached to an envelope, signifying that the person sending the letter or package has paid for delivery. (Stamps have been issued in other shapes, however: the circular stamps of New Zealand, triangular and pentagonal, and Sierra Leone and Tonga have issued self-adhesive[?] stamps in the shape of fruit, Bhutan has issued a stamp with its national anthem on a playable record, etc. Stamps have also been made of material other than paper, commonly [embossed] foil, and the German Democratic Republic once issued a stamp made entirely of synthetic chemicals.)
The adhesive postage stamp and the uniform postage rate was devised by James Chalmers[?] around 1834. The same ideas were published by Rowland Hill, in Postal Reform: its Importance and Practibility in 1837. In it he argued that it would be better for the sender to pay the cost of delivery, rather than the addressee who could refuse the letter if they could not or did not want to pay, as sometimes happened at the time. He also argued for a uniform rate of one penny per letter, no matter where its destination. Accounting costs for the government would thus be cut; postage would no longer be charged according to how far a letter had travelled, which required each letter to have an individual entry in the Royal Mail[?]'s accounts. Chalmers ideas were finally adopted by parliament in August, 1839 and the General Post Office started the Penny Post service the next year.
The first postage stamp was the Penny Black issued by the United Kingdom in 1840 with Queen Victoria on the stamp. Because the United Kingdom issued the first stamps, the Universal Postal Union (or U.P.U.) grants it an exemption from its rule that the identification of the issuing country must appear on a stamp in roman script for use in international mails. Before joining the U.P.U. many countries did not do this (e. g. the "bullseye" stamps of Brazil); there are very few violations of the rule since this time, though one example is the U.S. Pilgrim Tercentenary series, on which the country designation was inadvertently excluded. Because of this the numerous early issues of China and Japan often confound new collectors unfamiliar with oriental scripts. A stamp must also show a face value in the issuing country's currency. Some countries, including the U.S. and Britain have issued stamps with a letter of the alphabet or designation such as "First Class[?]" for a face value. Because of the U.P.U. rules their use is restricted to domestic mail, but breach of this rule is often tolerated. (Exceptions to this are the British "E" stamp (intended to pay the rate for mailing letters to Europe) and the South African "International Letter Rate" stamp.)
Since their inception there have been numerous innovative developments in how stamps have been dispensed and sold. Recently one has been able to print up postage stamps from one's personal computer. In 2002 the United States Postal Service licensed Stamps.com[?] to issue NetStamps[?], postage that can be printed up on special labels and, unlike previous postage the USPS licensed individuals to print up on their computers, these stamps can be used on any date, not just the date one prints them up. (There are other types of computer-vended postage[?] as well.)
Postage stamps are sometimes issued in souvenir sheets containing just one or a small number of stamps. Souvenir sheets typically include additional artwork or information printed on the selvage (border surrounding the stamps).
Stamps should be distinguished from cinderellas, stamp-like labels that resemble, but are not, postage stamps. Cinderellas might be commemorative labels, such as those issued to support the Transmissippi Exposition in Buffalo, New York (USA) in 1901 (one of these has now been converted into an actual postage stamp), or may be postage stamps for imaginary countries[?]. Clifford Harper has even designed "anarchist postage stamps".
"Test stamps" are not actually postage stamps, not being valid or intended for prepayment of postage, but are for testing printing processes, equipment, and the like.
Types of postage stamps
Some countries are known for producing stamps intended for collectors rather than postal use. This practice produces a significant portion of the countries' government revenues. This has been condoned by the collecting community for places like Liechtenstein and Pitcairn Islands that have followed relatively conservative stamp issuing policies. Abuses of this policy, however, are generally condemned. Among the most notable abusers have been Nicholas F. Seebeck[?] and the component states of the United Arab Emirates. Seebeck operated in the 1890s as an agent of Hamilton Bank Note Company[?] when he approached several Latin American countries with an offer to produce their entire postage stamp needs for free. In return he would have the exclusive rights to market the remaiders of the stamps to collectors. Each year a new issue of stamps was produced whose postal validity would expire at the end of the year; this assured Seebeck of a continuing supply of remainders. In the 1960s certain stamp printers such as the Barody Stamp Company[?] arranged contracts to produce quantities of stamps for the separate Emirates and other countries. These abuses combined with the sparse population of the desert states earned them the reputation of being known as the "sand dune" countries.
The combination of hundreds of countries, each producing scores of different stamps each year has resulted in a total of some 400,000 different types in existence as of 2000. In recent years, the annual world output has averaged about 10,000 types each year.