Silk is incredibly soft and luxurious but sewing with it can be tricky if you're not familiar with how it behaves. However, you don't need a fancy sewing machine to work with silk—it’s easier to sew than most synthetic fabrics.
Preparing the Silk
If you plan to wash your silk garment, make sure to prewash the silk first. Soak the fabric (including linings, interfacings, zippers, etc.) in warm water for about 20 minutes. After soaking, press the fabric on the wrong side while it's still damp, then let it rest for 24 hours.
Note: Some commercial silks have finishes that might change after washing. For example, charmeuse or satin will become softer but less shiny, and silk velvet should always be dry-cleaned to keep its texture. Always test a small piece of fabric before washing the entire garment.
All silks from Silk Wholesalers are prepared for dyeing and don't have any finishes except sericin, a natural substance from the silkworm.
Needles
Always use new needles. For lightweight and medium-weight silks, I use a No. 70/10 sewing machine needle.
Thread
For light and medium-weight silks, 100% cotton thread is best. It’s weaker than silk, so if a seam breaks, the fabric won’t tear. For heavier silks, you can use poly/cotton thread, but keep in mind that polyester doesn't take dye, so it may show up if you dye your garment later. I like to use silk thread to sew undyed silk garments.
Machine Tension
Set your machine's tension to a lower setting (around #2 or #3).
Stitching
For fine silk, aim for 10-12 stitches per inch. For heavier silks, 8-10 stitches per inch works best. The finer the silk, the smaller the stitch! For example, on my Bernina sewing machine I use a stitch length of 1.5 to 2 depending on the silk I'm sewing. I also apply some tension to the silk by holding it taught when I sew.
Pins
Use silk pins to avoid leaving marks. These pins are very sharp and won't damage the fabric threads. Only pin the seam allowances and darts. I use Clover Silk Pins.
Interfacings and Linings
Use lightweight fusible interfacings with care, as they can change the feel of the silk. It’s best to avoid fusibles on very fine silks. You can use silk Organza as an interfacing. For linings, choose fabrics lighter than the silk, like Habutai, Organza, or Cotton. Avoid synthetic linings as they can ruin the silk’s drape and feel. For added body, silk Organza or Paj can be used. Use Habutai in areas that need more support, like armholes.
Zippers
Use lightweight zippers, like nylon coil zippers. For the best results, sew zippers in by hand using a No.10 sharp or embroidery needle.
Seams
Finish all seams to prevent fraying. For lightweight silks, use French or flat seams. For heavier silks, use bound or Hong Kong seams.
