Great Britain Stamp? Counterfeit?

Hi xyL,

It is a stamp and as Puzzler says it was printed directly on to the newspaper wrapper and is considered "postal stationery" along with postcards (or "postal cards" in the US), registered envelopes, letter cards etc, all which have been available with the stamps already printed on the paper.

In the UK there have been two main forms of postal stationery: (1) items issued by the Post Office and (2) "Printed to Order" items which have been prepared by other organisations, had the stamps printed by the Post Office who returned them to the organisations for them to use. Sometimes the same dies were used for printing both kinds, sometimes they were different. In this case the only difference is the small dot after the word "HALFPENNY".

They are valid stamps and for most of the last century could be cut out from the postal stationery and stuck on to other envelopes for postal use (as long as they hadn't been used already and the original item was still valid for use). Some dealers in the 1910s and 1920s (and later) used to create novelty items by doing this. It was also a way of getting value back from old postal stationery that you no longer needed or had bought at a discount.