I used to press mine. Then somewhere - maybe on QB - I read not to press it. So I sew it onto the front keeping the raw edges even. Then turn it to the back and hand stitch - unless it's a baby quilt and will get more washings. The fabric on the outside of the binding takes a tad more fabric to turn then the inner fabric. It works better - for me. If there is a crease in it from pressing it seems the inner part of the binding is sort of 'bunched up'. With no crease the binding can turn and lay better; it has for me anyway.