I do a lot of fleece blanket prep for groups doing Project Linus blankets, and my experience is that fleece stretches much more WOF than length wise. Stretch varies a great deal from one piece of fleece to another, and there are some that are extremely stretchy (usually the lower quality fleece). In fact I will not cut fringe on the stretch side for children to knot, because it usually results in a very messy outcome.