During the Korean War (1950-1953) and for at least a decade after the war South Korea (ROK) was counted amongst the poorest nations in the world. As late as the early 1960s the average Ethiopian or Ugandan was richer than the average South Korean. And yes, even the average North Korean was (probably) richer than the average South Korean at the time.
Times have changed a lot since then, but shown here is an item showing how during those times anything was reused when something had to be created. In this case a postal card from 1946 (listed as UPC1 in the KPSC) was reused to create a “postal ID card” on the back of this card. The card folds in half so it can be placed in a pocket, easy to reach for when asked to show some ID.