Back in 2018 a short article was published that described South Korea’s unusual souvenir sheet (S/S) that was issued in 1966 for commemorating the 6th Postal Week. What is unusual about this S/S is that it was only issued with a red overprint. There was not a single stamp issued to accompany it. The S/S was originally printed for the 5th Postal Week, but was never issued. So to save money, the unused souvenir sheets were simply overprinted for the 6th Postal Week.
What prompted the author to write this article is that a piece of plain paper with only the overprint was found. This overprint on paper was possibly a trial run for printing the overprint before being used on the actual S/S. The author is asking our readers if they know anything about this type of printing. The author had never seen a similar piece of paper overprinted.