Video references:
Missouri Star Quilt Company – uses 1.75” cut for flange fabric and 1.5” cut for binding fabric
https://www.youtube.com/watch?v=HAQWwwAa2K0&t=729sJordan Fabrics – uses 1.5” cut for flange and 1.25” cut for binding
https://www.youtube.com/watch?v=EB0rc76kVV4&t=2s
Steps:
These instructions assume knowledge of attaching regular binding. In these directions the binding fabric refers to the color that will wrap to both the front and the back of the quilt. The flange fabric refers to the 1/8” accent that will show on the front between the binding and the quilt. These directions are for the 1.75” cut for flange fabric and 1.5” cut for binding fabric.
Calculate the number of fabric strips needed the same way as for regular binding. You will need that number of strips of each color.
Cut binding fabric strips at 1.5” wide.
Cut flange fabric strips at 1.75” wide.
Sew with right sides together the binding color strips to each other end to end, press seams open.
Sew with right sides together the flange fabric strips to each other end to end, press seams open.
Sew the long edge of the binding and flange fabrics together. Offset the seams so that you don’t end up with seams for both strips in the same place.
Press the seam of the joined fabrics toward the binding fabric.
Fold the binding in half lengthwise and press.
Sew the binding to the back edge of the quilt, with the flange fabric up and the binding fabric against the back of the quilt. Use a seam of just under 3/8”. This seam allowance will vary slightly depending on the thickness of your batting. Sew a few inches and test that your seam allowance works!
Corners and the final join are done the same as for regular binding. On the final join try to match the seams so the binding fabric and flange fabric are aligned.
Wrap the binding around to the front and stitch in the ditch on the seam between the binding fabric and the flange fabric. You will be sewing on the flange fabric so match your top thread color to the flange color. The goal is to sew so that your stitches on the back will be slightly inside the binding.