Interfacing is an extra layer of fabric that provides shape and support in detail areas of the garment. Interfacing is frequently used in collars, cuffs, lapels, necklines, pockets, waistbands and opening edges.
Types of Interfacing
The two basic types of interfacings are sew-in and fusible. Both are
available in woven, knitted and non woven versions, and in a variety of
weights, ranging from heavy to sheer weight. The rule of thumb is that
the interfacing should always be slightly lighter in weight than the
Choosing between a fusible or a sew-in interfacing is really a matter of personal preference. In general, fusibles provide slightly crisper results. Because fusibles "set" the yarns, they’re an excellent choice for fabrics that fray. However, some fabrics do not react well to fusibles. Theses include metallics, beaded, sequined or re-embroidered fabrics, rayon and acetate velvets, most brocades, fake furs, leather, vinyl and openwork fabrics, such as lace and mesh.
Always test the fusible interfacing on a scrap of the fashion fabric before you begin to be sure it works and that you like the results. Most people think of fusibles as easier to use and they are, as long as you take time to follow the manufacturer's fusing directions carefully.
For more sewing tips, see Simplicity's Simply the Best Sewing Book.