The minimalist, unadorned picture, with no crown on the stamp or any other decoration, was approved personally by the King. "The feedback we got back was that he wanted it to be simple," said Royal Mail director of external affairs, David Gold. "It's a very human image, with no embellishment," he said. The design was also intended to provide continuity, influenced by the classic profile of Queen Elizabeth II created by the artist Arnold Machin in 1967.
The new stamp is even more pared back and stark. It does not have any crown or royal symbols - unlike many of the predecessors, where kings' stamps often include an image of a crown and queens are depicted wearing a crown or diadem. "It was 70 years that we had the same monarch and since 1967 we've had pretty much the same stamps," said Mr Gold. He said people would now have to get accustomed to seeing the new image on everyday first- and second-class stamps.
Britain's postage stamps are unique in not showing the name of the country, and the new stamps have nothing except the King's head, the price and also, now, an attached barcode. The design is based on a sculpture made by artist Martin Jennings for the new King Charles coins - with the image then digitally adapted for stamps. Millions of new stamps are being printed, which will be used concurrently with those of Queen Elizabeth II, which will be sold until the old stocks run out.
The image released by the Royal Mail is for so-called "definitive" stamps, which are the regular, plain, non-commemorative postage stamps. Some of the first sheets were unveiled at the Postal Museum in London, which is showing an exhibition called the King's Stamp.
King Charles becomes the seventh monarch to appear on stamps - Queen Victoria was the first, in 1840, when her profile was shown on a "Penny Black".
The picture of Queen Victoria used on the first stamps originated from an earlier sketch drawn when she was 15 years old, and that continued as the image used until her death at the age of 81.
King Charles has been an inveterate letter writer - figures from the Duchy of Cornwall suggest he personally wrote 1,830 letters in his final year as Prince of Wales, in response to more than 50,000 sent to him by the public.
His letter writing when Prince of Wales also drew him into accusations of meddling in politics.
During the Covid pandemic he wrote a personal letter praising the importance of postal workers as a "point of daily human contact, a friendly, familiar face", addressing his envelope to "Everyone at Royal Mail".