10 Won Blue stamp; non-convertible (Socialist) currencies, 2nd issue

North Korea's 1978 currency reform created a two-tier system separating foreign exchange from domestic money, but the 1986 non-convertible reissue pushed that segregation further by targeting the domestic population with blue-overprinted notes explicitly barred from hard-currency transactions. The stamp itself — applied over existing stock rather than printed on new paper — was an administrative shortcut that kept production costs minimal while achieving the policy goal of currency segmentation.

Surviving examples frequently show the blue stamp applied unevenly, with ink bleed into the surrounding paper fiber, a known characteristic of the overprinting method used on this series.