Inquiring minds

If they did a brush torture test, who would win? Would it be a Boar, or a Badger or a Horse or a synthetic or some other critter? I'm not talking about manufacturers here we'll assume any such brush is well made as far as the handle and knot is concerned.

Also how would you design a test like that?

Maybe subject it to different cleaning solutions and lathering for weeks or months on end or throwing it around the room? Maybe freeze it in an ice cube or mix it in with my pasta the next time I make italian.

What do you think?

I would think that Synthetic would fair the best, especially over time. They are a lot more forgiving and you don't get the wandering stray hairs like you do with natural bristles, they flex instead of break...etc.

Badger would beat out over boar, just look at all the antique brushes. You can still find plenty of badger knots still in good shape, but most of the old boar knots, even if in good shape once ya start fluffing them they break and lose bristles like crazy.

I have no idea about Horse, never used one.

Synthetic would be the most durable, it's designed to be more durable than biologic materials with respect to temperatures and chemical reactions.
After that, I think it would be depend on the type of testing done.
Boar can handle heat better than badger. Badger can handle cold better than boar. Horse is somewhere in between.
Finer hair survives over time better than coarser hair so badger would win that one followed by horse followed by boar. Although, properly oiled horse, camel, and boar hair can last for centuries.
Cleaning solutions depend on uptake of the chemicals. The more chemicals the hair uptakes, the sooner the hair will fail. So boar would hold up better than horse which would be better than badger.

And now for some oddball stuff I've seen over the years - luckily not with my brushes.
Large insects like roaches, moths, flies/maggots, spiders seem to prefer boar over badger because they can get between the bristles. Small insects like mites, fleas, ants, gnats seem to prefer badger over boar. I don't know how horse holds up to parasitic invasion.
Badger is more susceptible to mold than boar, but boar is more susceptible to mildew.
Mice will make a nest out of a badger brush, but leave a boar brush alone. Raccoons will take whichever has the shinier handle. Bear will ignore both and eat the soap.
Cats prefer to play with badger brushes, dogs prefer to chew on boar brushes.
Children with scissors prefer to reshape badger brushes over boar ones.
No brush stands up to fire, but ivory handles sometime survive.