The brand of wool batting is very important. Hobbs Heirloom wool is the only one I would use. It does not require pre-washing and shrinks about the same amount as cotton batting. Quilting lines need to be 4" apart or less. Here is the website with information on this batting:
http://www.hobbsbatting.com/products...washable-wool/
Quilter's Dream wool batting is also popular, although there was a long thread here some time ago about a bearding problem with it. (I can try to look up the thread if you are interested.)
Where are people finding wool and polyester batting? Is it 80/20? I have not seen one. Brand?