The type of BRUSH depends upon what you are using it for!  As a group, bees
don't like a brush for two different reasons: Bees get entangled in the
bristles, just like being caught in your hair, and this arouses them.  Often,
probably most of the time, the brush is being used ROUGHLY and RAPIDLY,
something easily seen by the bee and they are aroused.
If you are using a brush to gently move bees around on a frame as you inspect
it for brood age, disease, or whatever, that is akin to using a shovel to put
icing on cookies!  Why not just use your bare fingers, and gently push the
bees aside!  You will rarely be stung; but DON'T DO IT WITH GLOVES!.  But if
you really want to use some type of brush, goose feathers are wonderful, and
you just keep one or two stuck in your hat.  In my 65 years of beekeeping, I
try to teach beginners you can always do the best work bare-handed; and throw
bee brushes away because their use makes bees upset.  Look around your area,
find some geese, and collect some goose feathers.  They are next best to bare
hands.
Someone might ask about capped honey frame removal.  I use preferably
BENZALDEHYDE or "stinky" BeeGo and a fume board.  Many beekeepers use a bee
brush and worry about being stung.  I have removed 30-40 supers of honey in a
2 hour period dressed in shorts and veil; but I would have to put on my bee
suit to remove just 1-2 supers of honey if I brushed the bees.
George Imirie - Wow, my bees are chafing at the bit to nectar collect!