Here's a link to the Hobbs batting website. Their "report" lists no shrinkage for the wool. They say it's the only bonded resin wool batting on the market. I thought I have seen elsewhere that the no shrinkage is guaranteed, but perhaps I am wrong on that. I don't have a package here or I'd look to see if it says "cool dryer" on the package.
http://www.how-to-quilt.com/articles...-batting.shtml