I haven't made a quilt out of velveteen, but have used it to sew quite a bit of clothing. Most velveteen is cotton and yes, it can be washed. Because of its nap, it has a tendency to "crawl" (layers shift) as you sew, so using a walking foot is almost a necessity. I agree that a crazy quilt is a good idea; otherwise a very simple pattern, because piecing velveteen would be a whole different scenario than regular quilting cottons.