Billiard balls and playing cards. Belgium is world leader in both.
Edit: forgot to add pigeons. Belgian competition pigeons are the most expensive in the world.
Edit 2: Belfries. Clock-O-Matic is a Belgian company and world leader in the automation of Belfries. It's not that hard because most Belfries are located in Belgium and France, if not all of them.
Damn. This actually makes me want to live in Belgium.
If not for the billiards,then for the church bells. If not for those, then for the competitive pigeons... Then the cards. (In that order)
Man, it feels weird to think of USPCC as a Cartamundi subsidiary, but I guess you're right — since 2019 (had to look that up) Belgium really has been the playing-card hub of the world! (A little American patriotism just died in me...)
USPCC only makes for a fourth of Cartamundi's revenue. And to make it even more Belgian, Cartamundi is still run by the same two families that founded the company 6 generations ago Each family owns 50% of the shares.