I decided to try a couple of "trimless" interior doors in my add-on room, like this pic. No trim, no cut, line etc. Just smooth drywall up to the actual door opening.
It turned out pretty well, but the problem is that I'm not sure the proper way to do it. I just ripped the trim off some cheap standard interior pre-hung doors, installed the frames in the rough openings, and butted the drywall up to it, filling in with mud as needed to achieve the smooth edge.
The problem is, obviously, that some of them are cracking where the mud is very thin on the wood door frame, and doesn't stick to the wood very well. When the door gets slammed or slightly flexes the frame due to use, it creates cracks.
Can anyone enlighten me to the correct way to achieve this effect to prevent it from cracking?