"These brushes are OK, but not good quality. The bristles are too thin and weak, and don't hold shape at times. I have now cut mine to shape to make it a fine finish brush as the bristle pile was pointing in several directions after one use for painting with primer/undercoat and then cleaning it.
Then again, they are cheap enough to use once and throw away without spending time and money cleaning them. But I won't buy them again unless planning to a small job and throw away due to inferior quality compared altenatives available for a little more. If you only paint once every few years, so why not spend a few bob on a good quality brush set and look after them after use. You'll get a better finish and less hassle."