I brush him when he's curled up next to me (which admittedly is very often), but I can't get the tangles out without a furminator or similar, and he doesn't like those.

His fur is about 1.5 inches long right now; it was longer but I have a groomer coming by every four months now. (He did not like the bath, and he did not tolerate the hair dryer, so he was moist and smelled of shampoo for a couple of days.)