As you can see there are those that always pre-wash and those that never pre-wash. I'm a never, doesn't mean my way is best but I agree with those who have suggested that you don't wash the back since the front wasn't. Wait until it is quilted. As to why I don't pre-wash. For one, I want to cut and sew asap and second, you really can't successfully pre-wash small pieces such as precut charms, strips so why do some and not others. Just my opinion.:) All pre-washers, keep it up-I admire your patience and perseverance.