Hello! I'm new to needle felting, and ordered some merino roving and needles on the internet today. I'm very excited to get started. I've read through most of the tutorials on this bored, but I'm really confused about one thing: what is the difference between wool batt and wool roving? I can't seem to find wool batt for sale on any of the websites I've been to. Is it crucial to this craft, or is it mostly used as filler? I'd appreciate any input!