I don't prewash either and have never had any problems. If I think I have a bleeder I test some of it. I like the way the fabric off the bolt behaves. I am not a starcher/best press user although I have all of it. I also wash the completed quilt in the regular laundry, no special handling, after it is done and throw it in a dryer as the recipient would. I know they wouldn't do any special care, so I don't. I also don't have any chemical sensitivities. I'm trying to remember if any of my quilts have really shrunk up to be noticeable. I can't remember any that have although I haven't measured them. I use warm and natural batting and I do like the crinkly look after washing.