Almost since the invention of the postage stamp in 1840 people have felt the desire to collect them. Known as philately, the collection of postage stamps is a hobby practised by many, and the finding of rare stamps is the aim of many. The first stamps, known as penny blacks, had a picture of Queen Victoria and were mass produced. Although sought after, the penny black is certainly not the most rare.
The Treskilling Yellow is the reflection of how a printing error can produce a rare and expensive product. It is a Swedish stamp made in 1855. Its face value is three skilling, but unlike other stamps with that denomination, it is yellow, not green. It is not clear how this misprint happened or how it got into circulation, but it is thought to be one of a kind. When it was last auctioned in 1996, the stamp sold for £1.5 million.
Benjamin Franklin Z-Grill
Often an unused stamp can be more valuable than a used one but, in the case of the Benjamin Franklin Z-Grill, that is not so. The Grill is an ink stamp that marks a postage stamp as used. At the time the Benjamin Franklin stamp was circulated in 1868 there were many different Grills in use. The Z-Grill type did not show up well on stamps so was discontinued soon after it was first used. Only two Benjamin Franklin stamps with a Z-Grill imprint exist and are valued at upwards of £1.9 million.
In the early days of Australian postage stamps, the Black Swan stamp was the first, originally printed in 1854. But, in 1855, a mistake while printing new stamps created a rare collectors item. Whilst printing a new run of Black Swans, the print plate for the words "Postage" and "Four Pence" were placed upside down. Before the mistake was spotted, 388 stamps were made, and the printer did not tell anyone. He let the stamps go into circulation where they went unnoticed and were used. Because they were used and discarded as if they were normal, only 15 full stamps are still in existence today. In auctions, they have ranged in value from £24,375 to £52,000
Post Office Mauritius
The first British stamps to be printed outside of the United Kingdom were made in Mauritius. Issued in September 1847, the first batch of stamps had a misprint. Instead of reading "post paid," the stamps had "post office" written on them. Two types were printed: the one penny red and the two penny blue. Only 240 of these stamps made it into circulation before the mistake was spotted. Today, 26 copies are thought to exist--14 reds and 12 blues--valued in the region of £1.0 million each.