The so-called Machin Definitive stamp, with its image of the Queen, has been reproduced in more than 130 colours since 1967 and reprinted an estimated 220 billion times.
It is considered to be one of the most reproduced images in the world, featuring a profile of the Queen by sculptor Arnold Machin.
Born in Stoke-on-Trent, he had a long association with Wedgwood potteries and also designed the profile of the Queen that appeared on coins from 1968 to 1984.
Before 1967, an image of the Queen taken by society photographer Dorothy Wilding was used on stamps.
Dominic Newton, Arnold Machin’s nephew and director and trustee of the Machin Arts Foundation, said: “He saw his task as creating a design with charm and dignity and yet without sentimentality, both a likeness of the Queen and an image of the monarchy. The result was an iconic design that has stood the test of time.”
Royal Mail spokesman Philip Parker said: “We are proud to mark the golden anniversary of the Machin Definitive with new stamps showing the evolution of this design classic.”
A set of six stamps were issued today, featuring different stages of the design.