Iron On Weft Interfacing is a great woven interfacing for adding body to jacket collars & lapels, pant & skirt waistbands, and any medium to heavy weight fabric. You could also use it for extra body on shirting fabrics where a stiff collar may be wanted. Iron On Medium Weight Weft Interfacing #T411HH-Black. Polyester and Rayon blend, 60" wide, Machine wash. Priced by the yard.