Nilla,
I have used fleece a couple times and LOVED the result. I loaded the selvage edge on the rollers. Don't tighten the rollers taut. I even had a bit of a sag in there. I"m not sure I would use a batt...I am thinking it would be pretty heavy, so maybe something thin? Warm and White is good..or maybe a thin poly. I even have quilted two layers of fleece for a throw and fringed the edges. I have a new machine on order, so will make a couple of those for practice when it arrives!