Yesterday I washed 4 yards of a fabric, I planned on needing 3 3/4 so allowed 4 yards for shrinkage, and off grain cutting from the shop. Here is what I ended up with, 5 inches shrinkage on 4 yards, then when I allowed for the straightening up of the fabric from off grain cuts at each end, I lost another 2 inches, altogether 7 inches, so I just squeaked by with the 1/4 yard extra. THEREFORE if you don't plan to wash, plan on that kind of shrinkage/off grain loss when you wash your quilt. This was only 1 fabric and I do not know the shrinkage rate of other fabrics I plan to purchase for this project. Just thought I would share the amount of shrinkage. It used to be that clothing fabrics that were not Sanforized could be counted on to shrink about 2 to 3 percent. I havent seen any preshrunk quilting fabrics out there, to avoid shortage if you plan to pre wash that amount would be a good amount to allow for shrinkage.:)