Originally Posted by
miriam
Some OSMG told me for practice try adjusting pressure with a piece of typing paper - no needle of course... Put the paper under the foot, try to pull the paper out forward/toward you. If the paper tears there is too much pressure. If too much, loosen the pressure until the paper pulls out. Then tighten it a bit. There is a sweet spot. Then check it with fabric. I usually adjust the pressure until it just holds the fabric. Not too tight not too loose. You don't want to be able to pull out fabric but you don't want it too tight either.
I'm thinking they put a silk setting on the drop feed dog knob or buttons so you aren't supposed to have to adjust the pressure for light weight fabric.
This is about what I learned too but it seems to be opposite of the page Janey posted unless I'm reading it wrong. I use just enough pressure to hold the fabric and move it along - which seems to be what you're describing, Miriam - like thread tension - thicker threads need less tension dial turns to get the same tension as a thinner thread. The page seems to say the thicker the fabric, the heavier your pressure will be.