I use my walking foot to hem sweat pants or any knit fabric. The doesn't streatch at all. Also, in attaching binding, I use my edging foot, works beautiful. I couldn't make it without my walking foot. I have a Bernina and the foot was approx. 60 bucks. A universal one will work, doesn't HAVE to be from Bernina. There are a lot of feet that are universal, as long as you have the adaptor, they will fit and work. Hope this helps. Mary