An invisible stiffening layer that is stitched between the top fabric and the lining or facing beneath, providing stability to a soft fabric so that it keeps its shape both whilst it’s being worked on and throughout its life. Anything that is cut on the cross, or in a concave or convex shape–lampshades, pelmets, cushion backs, tie backs and intricate shapes–will benefit from having at least a fine interfacing. A fusible interfacing will work as long as the fabric doesn’t react by bubbling or part releasing it–sewn in interfacing is by far the better practice.
Interfacings can be made of synthetic materials, wool, linen, cotton or hemp.