Here is a great post from the Shaving Brush forum from one of our resident brush makers @Rudy Vey !! It explains it really well and has a nice visual!I could ask all day! I currently use a 2 banded badger but I see you talk about 3 banded a lot. What’s the difference? What do you find you like more about each # of bands?

Stirling finest badger a real badger brush?
is the Stirling finest badger a real badger knot? for $32 I didn't think that was possible plus the reason i'm asking is on their site it says "The same finest badger fibers as found in our other brushes, now with fan knots rather than the more common bulb knots. Backbone, splay, and super-soft...

The 3 bands which are my favourites are the denser brushes. I find them softer tipped and splay a bit easier on my face!!