Nancy zieman sewing with Nancy sells a tape with sticky in the middle and peel away paper on each side. you peel away one side and place it on the one part with the edge right on the sewing line. Then bring the other side up to the tape an peel away the other paper. Carefully fold under and match the edge to the sewing line. Then you could carefully hand stitch the opening closed. The tape would reinforce it some for future use.