I don't pre-wash my fabrics. I like the "crinkle" look that my quilts have after I've made them & washed them. If I wash my fabrics before making my quilts, it causes them to pre-shrink & I don't get as much crinkle that I like with my quilts. I've heard that you should never pre wash the pre cuts like jelly rolls (2 1/2" x 40" strips), layer cakes, etc.