Hat bodies, made from either felt or straw, are blocked into hat shapes by way of hat blocking machinery. The shape is determined by the specific mold being used that fits these machines.
Machines like these replaced hand-blocking, an art or craft that still continues to this day. Notice below links that will take you to sturdy vintage papier mache hat blocks from mid-20th Century Hollywood. We sell these to milliners and/or collectors of unusal items.