I would have never thought it but I found that a Purdy 2 1/2 inch "thick body" angled brush is awesome for cutting edges on everything! I used it on wall/ceiling joints, base moulding/drywall joints, etc.. I used to use/try thinner body Purdies in 1 1/2 or 2 inch (sash/trim/XL Dale models) and get frustrated with the skipping, unevenness, bristles gapping, etc.. I used the "fat" Purdy 2 1/2 incher on a lark, too. It provided great, smooth flow--I'm guessing it is because the heavier body carries more paint to keep the flow going. It squished into a very sharp edge, which was the biggest surprise. I now love cutting!!! This brush was left by a painter who never came back for it--I told him 2X, too. The fact he was using it should have been my first clue it was the hot ticket. I never witnessed what he using it on though or I would have been on it earlier.
Oh, yeah, he put a screw hook between the handle and the bristles' metal band to hang the brush bristles-down on a can rim or grate. Very handy! I was able to scrape the old paint off the handle--it's a Purdy 2-1/2 XL Glide model.