​How To Finish Armhole Edges With Pre-Packaged Bias Binding

A pre-packaged bias binding is conventionally pre-folded in either single or double fold style and ready to use. In this example, a double fold pre-packaged binding is used to clean finish an armhole edge. The binding is attached similar to a single layer bias binding, but in this case,  the binding's pre folded crease lines are used as a stitching guide. 

1. Open the double fold binding strip and fold one of its ends toward the binding's wrong side at about 1/4"-1/2". Align the folded edge created with the the garment's side seam located at the underarm with face sides touching and edges aligning. Insert a pin perpendicular to the edge to secure the layers together. 

2. Continue aligning and pinning the binding edge to that of the armhole, inserting pins perpendicular to the edges to keep the layers aligned. Pin until you arrive at the binding starting point. At this location trim the binding strip excess such that its end overlaps the folded end by approximately 1/2". Place the trimmed end of the binding on top of the folded end and insert a pin to keep all layers aligned. 

Prior to machine stitching, it helps to hand baste the binding and armhole edges as this will provide a lot more stability during the machine stitching process. 

3. Machine stitch the binding strip following the crease line as a guide. You can stitch directly on top of the crease (if this is more comfortable for you) or a little to the right of the crease.

4. Once stitched trim the seam allowance excess in areas where it  appears wider, or but about 1/16" along the entire edge. Trimming some of this excess will help you fold the binding layer over the armhole edge much easier. 

5. Next, let the double fold binding wrap around the armhole's raw edge- this happens intuitively following pre-folded lines. All raw edge should be fully enclosed in the slot created by the double fold binding. Iron the binding in this alignment to secure. If your binding application is exposed you can blind stitch or topstitch the binding in this position. In this tutorial, the binding is folded under and topstitched. In this case, fold the binding one more time toward the wrong side of the garment and iron the binding layers in this position. 

6. Again, it is extremely helpful to hand baste the  binding layers flat as this will prevent them from shifting out of place or rippling under the presser foot. The binding acne be easily removed with a seam ripper when no longer needed. 

7. From the wrong side of the armhole machine stitch the binding following its open edge as a guide. It may take some practice applying this stitch smoothly, especially at the more curved area of the underarm. 

Once stitched, remove the hand basting with a seam ripper and iron the finished armhole edge to flatten and even out any tension created by the stitch.