I used to was everything when I sewed only garments, but since becoming a quilter, I do not wash my quilting fabric, and I have never had a problem, but I also use a couple of color catchers in the wash and have never used an obvious "bleeder" I like working with nice crisp unwashed fabric. It doesn't fray so much and just seems nicer to work with. I usually used w & n batting and I like the crinkle I get when washed. If I come upon a piece of fabric I want to use that I have washed, from my earlier days, I just starch the daylight out of it and press it well.