I don't wash my fabric and I hand piece and quilt. I use 100% cotton thread but I don't know if that is a must. I like to do everything period correct if it is the 1920's or 1800's. When I am finished with the quilt I wash and machiine dry it. The fabric and batting shrink at the same time. It gives the quilt a vintage/historical look. The exact look I want. I do know people who machine qquilted it and it gives the crinkled look too. And you can use any pattern you want.