Stamp collecting is a hobby shared by many people around the world. It is one of those unique past-times that you are either into or you are not, rather like mountain biking or buying and selling gold in the Bullion Vault. 

Interestingly, before stamps were invented, postage payment worked in a different way. Instead of the sender paying to send a letter, it was the person who received it that was required to pay. It was Sir Rowland Hill, born in England in 1795, that turned this practice around. His plan for reform introduced the idea of envelopes and adhesive stamps, as well as lowering the cost of sending a letter and making the process all in all, a lot easier. 

There are a wide variety of stamps which can be collected, and this is part of the charm of this hobby. Of special interest to collectors are stamps which are rare, famous and expensive. The Penny Black, created in 1840, is one such example. This was the first stamp ever used to enable prepaid postage, and bore Queen Victoria's profile. It was not even perforated and was only used for a year. This makes it both famous, and valuable, definitely worth describing as a collectable. 

Believe it or not, there is a stamp which is much more expensive than this initial one. The Treskilling Yellow is worth around $80 billion/pound by weight due to there only being one known copy. It is thought that it was created probably accident, when the equipment used to make the usual green Swedish three skilling stamp and the yellow eight skilling stamp was mixed up, creating a yellow, three skilling one. 

Many different designs of stamps have been used over the years, and this has made sure that the hobby of stamp collecting has thrived and remained an interesting practice.