I haven't used them in awhile but, when I did, they made the most accurate HSTs I've ever achieved. As I recall, you cut two strips of fabric (two different ones) the width of the Thangles strip. Layer the two fabric strips right sides together and pin the Thangles strip on top. Sew on the dotted lines (no need to cut thread in-between). Cut on the solid lines. Make your stitch length a little shorter than you normally would, so the paper is easier to remove. I think I bent the paper back at the sewing line to weaken it there. Hold a finger on the sewing line and tear the paper off.