Real boar hair shaving brushes are cheap and have very stiff bristles. This makes them popular with shavers who like using hard shaving soaps to lather. Boar hair is thicker and stronger than badger hair, but much less softer. The bristles will soften over time through use.
Mixed hair bristle brushes typically feature a mix of boar hair and assorted grades of badger hair. This creates a stiffer shaving brush that exfoliates your skin and lathers up hard shaving soap with ease.