50 Won

The P#40 series spans a politically volatile stretch of Park Chung-hee's rule, issued between the 1969 constitutional referendum — which allowed Park a third term — and the 1972 Yushin declaration that effectively ended South Korean democracy for the decade. The Bank of Korea's domestic printing capacity had expanded significantly by this point, the Korea Minting and Security Printing Corporation having taken over production previously contracted abroad.

Watermarking was the sole mechanical security measure, a relatively thin barrier for a denomination that circulated actively in a rapidly industrializing economy prone to counterfeiting pressure. Worn examples are the norm.