I just had the same thing. The batting was some I tried from Connecting Threads, but I don't think it was the cause as I used it for some wall hangings with no problem.
I might just have used something called "Quilter's Cotton" from Hancock Fabrics. I haven't had good cottons shrink, but from now on cheap ones will get prewashed. I wash in cold water, and the quilt was dried on low.
I've never had permanent press Muslin shrink. I made shirts with it years ago, and they are still the same size. The muslin that really shrinks is the 36" wide variety. It's mostly for crafts and fitting muslins for dressmaking. It's cheap enough that you can make many trial fittings of a bodice and throw out the fittings that didn't work.
Last edited by Weezy Rider; 06-19-2014 at 01:50 AM.