can anyone throw any light on this question? I'm celebrating my 50th anniversary this year and it's estimated that more than 200 billion of me have been produced - what am I? many thanks (that's all the info I have)
Definitive stamps featuring Arnold Machin’s sculpted portrait of Queen Elizabeth II were introduced June 5, 1967. In the last 50 years, this portrait of the queen has appeared on an estimated 220 billion stamps