A flag I have designed for the Diplomacy board game, to replace the cardboard ones that come with the game.
I also printed on paper the flags of each nation, front and back, to glue them on the pieces. I include a pdf with the flags ready to print (Germany has an extra flag, there should be 22, I don't know what happened there).
I have also used these pieces for armies and fleets:
https://www.thingiverse.com/thing:713140
https://www.thingiverse.com/thing:714358
The author marked this model as their own original creation.