This technique for a simple, almost foolproof bias edge binding, is perfect when visible stitches or binding might detract from the finished product.
A single thickness bias binding is sewn right sides together around the opening. Bias strips will stretch very easily and can be used to stabilize an opening that should remain close to the body by stretching the strip onto the fabric, or as in this case, the strip can be eased onto the seam, making the bias strip a little looser. With the extra fabric eased into the seam, the pressed binding will lay flat around the inside curve of the arm opening when it is finished.
The seam allowance is pressed into the bias binding, or the binding is pressed over the seam allowance – however you prefer to think of it …
and the binding is folded once, keeping the fold line equidistant from the seam line. I took some care to make sure the fold is a consistent 1/2″ from the stitching line because that is a good width for the finished binding.
From the back, the bias binding covers the stitches of the seam that connects the two pieces of fabric. It is not necessary to turn the edge under because the bias cut silk will not fray. By not turning the fabric under a bit of extra bulk is eliminated and the pressed binding will lay flatter. The picture above is after the binding has been stitched in place from the right side.
Once the binding is pressed in place, stitch in the ditch or very close to the seam but on the wrong (bias binding) side. You can see the extra ease in the binding in this photo.
After the binding is stitched in place, roll all of it to the inside. The stitches should easily roll to the inside as well. Here is where you will see the benefit of having eased the binding to the fabric. After the binding is pressed from the inside of the blouse it will curve nicely with the armscye seam and the whole assembly should be lay flat.
This technique makes a very flat, bound edge with no visible seam. Silk fabric presses so nicely that the binding stays to the inside. A little extra insurance can be gained by tacking the binding to the blouse at the shoulder seam and the side seam.
For this blouse:
Fabric – Silk Charmeuse
Bias Strip 1.5″
Seam Allowance to attach the strip to the armscye 3/8″
Distance between stitches and fold line 1/2″
Finished width of bias binding 1/2″