Welt cord is one of the most popular trims used on slipcovers. It gives definition to seams and adds a tailored finish.
Trimming your slipcover with welt cord is a personal choice. It’s more decorative than functional even though it does a pretty good job at adding strength to seams.
You can make the bias fabric strips for your cord with self-fabric (the same as your slipcover) or contrast. For the cord itself I recommend a medium firm poly tissue core wrapped in a braided cover, size 5/32. Get resources here.
There is more than one method to make welt cord. I’ve tried them all! But at the end of the day here’s the one that works best for me.
1. Cut bias strips.
For size 5/32 cord (the standard for most slipcovers), you will need to cut bias strips 2″ wide if you sew your slipcover with 3/4″ seam allowance (that’s what I use.) Or, if you work with 1/2″ seams cut your bias strips 1.5″ wide.
FYI — fabric 54″ square will yield approximately 38 yards of bias strips.
2. Join and stitch ends.
Join 2 bias strips at a time, right sides together. Stitch 1/4″ seam. See images 2 & 3. Back stitch when you begin and end the stitch line. Don’t cut thread after sewing each seam. Just keep joining and stitching ends together until you’ve made 1 long continuous bias strip.
3. Snip the join threads.
When you finish stitching all ends together they will be loosely joined by a small length of connecting thread. Snip those threads. See image 4.
4. Wrap cord and stitch.
Center cord on wrong side of bias strip. See image 5 & 6. Wrap fabric over the cord, raw edges meet to the right. Using a zipper foot or cording foot, stitch through the two layers of fabric as close as possible to the cord.
Viola! Your welt cord is finished and ready to trim your slipcover.