I honestly never knew there was a rule about that LOL. I use whatever matches the best. I always adjust my tension for each project so I just play with my tension on a practice piece for a bit till I like how it looks then off I go ! I figure Brother put that tension adjustment knob there to be used not for decoration , so I use it ! I could not even tell you what settings I used from project to project because I pay no attention to them, I just turn tighter or looser till I like the results.