I use Hobbs 80/29 fusible batt for a lot of my machine quilting. It does soften up when you wash it as this removes the fusible. I hand agitate my quilts and then spin them. I then put them in the dryer until almost dry. If I want a flat look after washing, I block the quilt out on my spare room carpet on a clean sheet. If you block it until it dries, you will get an almost wrinkless look but softer. In wallhangings I like the stiffer effect so I don't wash those after quilting.