Silk charmeuse, being a luxury fabric, smooth and soft, can be one of the hardest fabrics to sew. It’s expensive and it is a must that you know how to handle such fabric. Charmeuse is medium weight, woven silk with a lustrous appearance.

Here is a sewing guide on how to do silk charmeuse, which I grabbed while having my morning cup of coffee.

Pre-treatment:

Handwash in cool water with a drop of shampoo, rinse several times, lay flat to dry. Dryclean if preferred.

Needles and thread:

Use a sharp regular needle in size 8-10.  Do not use a ball point or universal needle.  Always use a new needle when starting a new silk project.

Interfacing:

If you prefer a fusible, use the lightest weight you can find. Look for Silkweight, Touch of Gold, or other super-fine fusibles. By far the best interfacing for charmeuse is silk. Use silk organza for those areas that need a bit of crispness. Use a layer of self-fabric for those areas that need interfacing but need to retain a soft hand.

Seams, seam finishes, and hems:

Shorten your stitch length slightly for construction; if you normally use a 2.5 length, shorten to 2.0. For seams on the bias, use a zigzag stitch (2.0 length, 1.5 width) to allow the fabric to maintain the stretch of the bias. Seams will require finishing, as charmeuse ravels. The best solution is to use a French seam for construction. Stitch the first seam with wrong sides together at 3/8”. Trim to a scant ¼”, press the seam open, then turn right sides together. Stitch the second pass of the seam ¼” from the fold of the original seam. This enclosed seam is elegant, clean, and classic. If you prefer to use a machine stitched finish, keep it light. Use a 2 thread overlock seam on the serger, or trim the seam very closely and zigzag over the edges to finish. Hems are best done by machine, and should be as narrow as possible.

Src: http://www.emmaonesock.com/guides/silkcharmeuse.asp