being an avid user of simpson's wee scot brush.. i often wonder why larger brushes are the norm.. i understand that there's a luxury about them and everything.. it just seems like i'm missing something..

then this weekend i'm at an antique shop and i notice the knot size on several vintage brushes.. they all seem to be quite small.. around 18mm or less i would say.

does anyone know the specs on the older brushes? also.. when and why did we transition to the larger brushes of today?