Someone I know visited Seoul last month and secured these three Korean mint sets (2021, 2022, 2023) for me...
Yeah, it's a recreation of traditional mother-of-pearl and lacquer inlay work. The box is not printed that way, either. It has some relief to it, so they put some effort into making it look as "real" as possible for what it is (a box for a mint set).
I didn't realize they still minted the 1 and 5 Won for the proof sets. Those are very small denominations! Glad you were able to get the sets.
