How do university professors and staff design their ceremonial gowns?

Each university has its standard design.

Tradition dictates the gowns at older, established and higher-end universities. Most of the rest probably choose from a site like this.

Academics don’t choose or design their robes. The university has its own design as @janbb said.

What @janbb and @Earthbound_Misfit said.

When profs attend gown-worthy ceremonies at the university where they teach, that university provides the standard gown for the university that each obtained their PhD from. I’m told that very few profs carry their own gowns from post to post.

@ibstubro I wonder if the site you linked to is either meant to service universities in bulk, or trying to bilk students out of money for items that they should be borrowing from their soon-to-be alma mater. I’ve never seen anything like that before.

@dappled_leaves I suspect the site is for public universities and high schools?
There appear to be dozens.

@ibstubro Not sure what you mean by a public university, but if we’re discussing professors’ gowns, hopefully they’re not being marketed for high schools! It’s an odd thing, to be sure.