I was always told these things were just so that the thread didn't rattle around on the spindle. Little did I know they actually serve a practical purpose as well. My machine cover is plastic, so no need to worry about paint, but it would be nice if they help the thread pull smoother. I was nervous they might add friction & cause the thread to pull at a slower rate and more be taught.
Does anyone know if you're supposed to use wool felt or is the eco felt okay? (or is there something even better?)