I like my fabrics to have some body to them so leaving whatever type of sizing the fabric company put into it helps. I also use starch before cutting to help with the stretching out of shape while assembling. Then I use Elmer's Glue when attaching the binding and sometimes when I need to match seams so it will get washed once its all done anyway. I think in the past I have washed a backing if it was a solid black, navy or red due to possible bleeding. I use the color catcher sheets too to help with that problem.