I press my bindings because it's easier to control while winding it onto the binding holder. It unwinds as I sew it onto the quilt. I tried not ironing it, but it just wasn't winding well. The winder clamps to the end of the ironing table, so I press. about 30 inches, wind it, press another 30 inches and wind, until all the binding is pressed. With the winder clipped to the end of my sewing table I don't need to pin or clip the binding to the quilt as I sew it on.