The first time I saw this was a vendor at a quilt show and she used flannel. Old timely "inexpensive" flannel and the needle goes through like butter. I recently used muslin scraps from my stash and some of it needles with some difficulty. I'd you try the flannel get sure it is old type the same on both sides not the newer ones with a rayon type backing. I think it adds substance to your embroidery and helps make the knots and traveling stitches less noticible.