First stitch line from bottom opening to armhole:
Cut to first stitch line:
Press open in opposite directions:
Press right sides together, and make final stitch:
Press open french seam stitch. Then, steam press on the right side so that the arm hole open seams are now covered:
Topstitch armhole hem:
Or, blindstitch armhole hem:
What the final right sides look like:
Wrong side/interior stitch view:
