Mildew is the common name for a variety of fungi that can attack natural fibers and their blends when in conditions of warmth and moisture. If mildew has not eaten through the material completely, washable items can be washed in hot water with detergent, then rinsed thoroughly, and dried. If color remains (mildew comes in various colors--black, green, rust), then an all-fabric or mild bleach may be used, bearing in mind that bleaching will further weaken the fibers. When fibers and yarns break, a hole will soon appear.