You are a good man my friend.Not really, but the way I interpreted the rules of this thread - one only - I listed my top choice on that day.
My preference order varies from week to week, with badger and boar going neck and neck for the top spot.
Synthetic knots are a lot cheaper, so they make more sense for donations, but for me, they're a distant third.
I already know I'll bid on at least one of your brushes in the auction regardless of knot.
They're just too beautiful to pass up.