you can purchase fusable on a roll (like tape) that is 1/4" and 1/8" wide...it is what is used on the black bias for stained glass. it is not expensive= and is used with a bias tape maker to attach it to your leading.
it is available from clotilde's and nancy's notions. it is on the page with the clover fusable bias tapes.
i bought the roll of 1/4" i have now at joannes- it was very inexpensive....compared to the ready made fusable bias tapes.