Try filling your bathtub with hot water (as hot as possable) with gentle detergent. Let them soak for a long time and swish or do the grape stomp on them. If you are mixing colors, use a color catcher. It is the aggitation motions that cause the fraying. Drying in the machine will also cause fraying. If you have extremely hot days in the sun - dry your fabrics out side (print side should not be directly in sun)