Postage stamp prepaying. From when the first postage stamps were used, postmarks were applied to prevent the stamps being used again. The first stamp, the "Penny black", became available for purchase 1 May 1840, to be valid as of 6 May 1840. Two days later, 8 May 1840, the Two penny blue was introduced. The Penny black was sufficient for a letter less than half an ounce to be sent anywhere within the UK. Both stamps included an engraving of the young Queen Victoria, without perforations, as the first stamps were separated from their sheets by cutting them with scissors. The first
Postage stamp gum his invention of stamp gum in 1837. The world's first adhesive postage stamp was called the Penny Black. Many early stamps were not gummed, however, and some have been unable to be gummed due to shortage (for instance, the typewritten Uganda Cowry stamps of 1895). Extreme tropical climates were also a problem for Curaçao and Suriname. Some stamps, intended only for sale to stamp collectors, have been issued without gum, for instance the United States Farley's Follies souvenir sheets of 1933. On the first stamps of Great Britain the gum was called "cement" and was made from a mixture of