Mrs. SewNSew

Tammi did such a good job explaining about Tension Bugboos, but what about presser foot pressure?

I don't understand it and doing a google search gets you next to nothing about the actual adjustment procedure. Posts tell you how to adjust it, how important it is and that you should do it. Do What?

I am very unclear as to when it should be lighter and when it should be heavier. I know if it is off it can cause skipped stitches, uneven feeding, and even stretch the fabric. *Try and search fabric stretching and you get a lot of articles on sewing stretch knits grrrr.

Are there hints in how the fabric feeds as to what needs doing?