Having read the above posts I did not hear from anyone that it might be the backing fabric. So I will toss that suggestion in. As a professional longarm quilter I quilt many quilts in a year's time and only occasionally run into one that seems stiff after quilting. I use Hobbs batting, either poly or 80/20 and sometimes do dense quilting on a top. Even the dense quilted ones are soft and cuddly unless a stiff fabric has been used, usually as the backing. I have ran in to some wide backings that even after being washed they are still stiff.