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 paper also be identified when the paper changes either within the issue or with the next issue. When colored paper is used for the stamp, the ink colors are listed first and then the paper's color is listed next in "italics". Sometimes the paper is described as "ordinary", which simply means that the common paper of the period was used. Coated paper is usually not listed but may be surmised by the printing process used to print the stamp. For example, photogravure printing yields the best clarity when printed on coated papers. Examples of different security paper used on postage stamps.