FYI for large areas I use the 2" brush as is, but when I'm doing smaller stuff and and using the 1" brushes I sometimes take some scissors to the bristles and cut them down a bit so they are stiffer... All depends on the fiberglassing job I'm doing, a few years back I was actually doing so much fiberglassing with those brushes I developed some big hard calluses on my fingers from holding them for so many hours a day, the brush literately locked into place

can't say if that was a good or bad thing...