Recently, I purchased some raw silk for a spring jacket, even though I knew that it was problematic to sew. The issue with this kind of silk is with raveling – the seam allowances practically jump apart once you cut.
Here’s an example of what I’m talking about. To demonstrate what happens, I just cut this piece out, and shook it gently for a few seconds. Look at the raveling! It’s a nosebleed to sew!
I did a little experimenting before I began, and figured out this trick to keep the seam allowances intact. Know that this will use a little more fabric in cutting, but the results will be worth the fabric you’ll waste in preparing the garment sections.
After placing your pattern onto the fabric, thread trace the cutting lines through both layers of fabric, leaving large thread loops above the fabric.
Here’s a close-up of the loops of the thread tracing.
Cut out the piece, by cutting 3/4″-1″ away from the cutting lines. Having this extra wide seam allowance will give you the extra fabric you need to secure the final cutting lines on your fabric.
This is a close-up of the work.
Remove the pattern from the fabric. You see the loops of the thread tracing sitting above the fabric.
Pull the layers apart, as shown.
Now, cut through the middle of the threads to separate the two garment pieces.
The thread will now lie flat against the wrong side of the fabric, as you can see in the photo.
Next, go to the sewing machine. Make sure there is a fresh needle in the machine – a dull needle won’t pierce through the thick yarns in the raw silk.
If you have a walking foot, attach it now.