I usually pre-wash all my fabrics but sometimes I have been known to be making a project and decide to use an unwashed fabric instead of one I had planned to use. In that case I usually give it a good steaming with the iron and pretend it is shrunk enough to go in with my pre-washed fabrics. It is a dark color going in with lighter ones then I might put it in the sink with some hot water to see if it is going to bleed first.