FROG TAPE. I know it has been around awhile- but I just have to say this stuff is excellent (not on bumpy popcorn ceilings- that's to be expected).
My trim lines have never been crisper- this stuff is a million billion times better then the blue painter tape- Seriously!!! I suggest taping and painting the same day because after a few days it does start to lift off. Especially around windows when it is cold outside and warm inside. But if you tape the same day you paint the seal is superior- NO paint gets under the tape. Get the green stuff. It's worth it!