Interfacing gives support and shape to e.g. collars, lapels, facing, cuffs, ... It is available as a sew-in fabric or a fusible fabric, woven or nonwoven. It is cut in the same size as pattern pieces and fused or basted directly to the shell fabric. Seam allowance is required for nonfusible interfacing and optional for fusible interfacing.
For a coat, usually the following pieces should be interfaced:
- front + front facing
- side front (if there is a pocket on the princess seam)
- upper back (shoulder area) + back/neck facing
- neckline and armhole seam allowances
- collar, lapel
- buttonhole areas
- pocket areas, pocket flaps, cuffs, waistband
For my coat, the pattern required to interface a coat front (including front facing) and front side, neck facing, and seam allowances on the neckline and armholes. I decided to use fusible interfacing, because it is much quicker to iron than sew on by hand. I used this one:
1. Preshrink both shell fabric and interfacing and cut the pattern pieces. Seam allowances are optional for fusible interfacing. Put a pressing cloth on the ironing board (to protect the ironing board). Place a piece of shell fabric down on it.
2. Place the adhesive side of the interfacing to the wrong side of the shell fabric. Ahesive side is usually a bit rough.
3. Place a pressing cloth over the fabric and interfacing (to protect the iron from getting dirty with interfacing's resin). Fuse the interfacing according to manufacturer's instructions. I, e.g., had to iron a piece on middle-high heat without steam. Some interfacings require steam.
4. Place the interfaced piece on an even grounding and leave it there to cool down.
5. Now, it is time to underline the shell fabric. Only after that you can trace over pattern's marks for pleats, buttonholes, darts, etc., and sew the pattern pieces into a garment.
I will be showing you how to underline a garment very soon!