Heisenberg is one of the most famous men to ever wear the hat, but he’s not the only one. The pork pie style hat became popular during the ‘30s and ‘40s in the Great Depression era.

The "pork pie" is a rounder hat with a turned-up brim and a flat crown. Some men will opt for a boater. This style is a men’s summer formal hat made of stiff sennit straw.