it's pla based. But the only thing that makes it shine is good old fashioned elbow grease.

I had zero problems printing it. Just printed like good pla.
But it is a lot of sanding and polishing. And unless you have a low speed buffer, you're stuck with doing it by hand.
even on the lowest setting my rotary tool and buffer head melted the bronzefill.

But in any kind of model with crevices it's a real bastard to get it shiny.

For the protopasta steel filament I printed a simple flat shape. And I still can't get that stuff to look shiny. Bronzefill is real easy by comparison.