Batiks are the only fabrics I prewash. I wash them in hot water with Retayne and a color catcher. The catcher comes out clean. I dry them in the dryer.
I did wash some non batik fabrics once, because I was collecting them from a variety of sources, and some had that "basement" smell. After drying I ironed with Best Press, and afterwards wished I had starched. They were not as easy to work with as my new, nonwashed fabrics are.