• Does your costume have contrast trim around the edges? Never fear -- bias tape isn't as scary as it looks! This is a very beginner-friendly guide to double-fold bias tape application. This is double-fold bias tape. If you unfold it, you will see three fold lines. (This is the kind I recommend for trimming the edges of a garment.) If you are using single-fold bias tape, you will see only two fold lines, and you will have to use your imagination or a ruler to divide the wide center section in half in order for it to wrap both sides of your fabric.   Lay your bias tape flat and find the side that is slightly narrower than the other. You will