Sewing with Silk
One of the things that keeps people from buying and working with silk fabric is fear. Fear that it's delicate and they don't want to damage it, fear that they'll mess it up, fear that their skills just aren’t up to snuff. So here is a crash course primer on how to work with this lustrous fabric.
First off, pre-wash the fabric using your preferred method. The Caveat is that Silk Velvet and Watered Silk should always be dry cleaned. Otherwise, either hand wash or machine wash the fabric in preparation of working with it. YES, it CAN change the hand a bit, especially if it was heavily started to begin with. But you can re-starch your silk during the sewing process.
Once you have washed and dried the fabric, iron it. Just like with cotton, linen, or synthetic blends, you don't want to cut wrinkles in to your silk. Use a pressing cloth to protect your fabric from scorching. If you have a very good iron, you might be able to get away without a pressing cloth, but if you are at all uncertain, far better and scorching that happens occurs on the pressing cloth, NOT your fashion fabric. While you can remove many stains from silk, scorching is basically fire damage. There's no coming back from that.
If you don't want to buy a cotton press cloth, you can make one from a scrap of silk organza. Simply cut the scrap approximately one yard by one half yard, surge the cut ends to prevent fraying, and you're good to go. Make sure it's SILK organza. Polyesters can melt under high heat, and again, if it melts in to your silk, there's no coming back from that damage.
After you have ironed the fabric, lay it out like you would any other fabric for patterning. Make sure the entire piece is fully supported on your cutting surface. Silk is SLIPPERY! That zero friction is one of the difficulties of working with it. If the full weight of the fabric isn't supported, then when you start cutting out the pieces, the fabric can slip right off the cut surface, which will pull the fabric and pinned pattern pieces out of alignment, pretty much wrecking the project. You can recover from this, but why cause yourself unnecessary agony?
For pinning and cutting--If you are comfortable with pattern weights, then by all means use them. If you prefer pins, then I use Dritz Ultra Fine Pins. Be cautious about jamming the pins into the cut surface underneath. Because they are ultra fine, the point can dull very quickly. As long as the pin shaft has not bent, you can always sharpen them using the emery pad on an old fashioned Tomato Pin Cushion.
When you're satisfied with your pinning, it is time to cut. Now, I have not used rotary cutters on silk, but that is mostly due to my inability to use rotary cutters without slicing my hands to ribbons. I use Gingher Dress Shears with a micro-serrated edge. The micro-serrated edge will hold any slippery or slinky fabric in place for a clean cut. If you use a standard knife edge set of scissors, it becomes an exercise in frustration as the silk slides off the blade while cutting.
Once you've cut out, transfer any markings using either Tailor's Tacks or Pin Marking, or a smooth tracing wheel and wax paper. I do not recommend a serrated tracing wheel for any fabric due to the serration pokes tiny holes in whatever fabric you're marking, which MIGHT close back up, but again, why risk the mayhem when alternatives are readily available?
Sew as usual, but I do recommend using silk thread when sewing silk fabric. I also recommend shortening your stitch length to 2mm, or approximately 13 stitches per inch. The filaments on silk threads are considerably finer than cotton, linen, or rayon threads, making the thread virtually invisible against the fabric. And silk threads will run through your machine the same way cotton, linen, and rayon threads do. Use the finest size needles for your machine and for hand sewing.
Originally, this post was published in June, 2016. I am adding this paragraph here to reflect new knowledge. When I originally published this post, I did not know what I now do about Seam Slippage. Given this new to me knowledge, I wanted to include a paragraph about finishing your seams, as a preventative to seam slippage. My first recommendation is to flat fell your seams, but a good alternative is french seams. Both work well in giving a clean finish to your seam, and in preventing seam slippage.
And that's it. Follow these guidelines to make sewing with silk less stressful. For additional tricks and tips, read this post from threadsmagazine.com. I think the only thing we disagree on is thread type. Otherwise, everything there is what I also recommend. Happy sewing!