Some do, some don't. I've had better luck with the major brands than the cheaper ones. Whenever possible, I prewash using a color catcher sheet or 2 if they are mostly darks. I've made many quilts with batiks and have never had a problem. I just finished a quilt made from a Tonga Treats strip pack that wasn't prewashed. I used a few color catchers in that one and it came out just fine.