My concern with prewashing stems primarily because of the chemicals contained in the fabrics from the manufacturing process -- I am asthmatic, and I sure don't need anything adding to that. That being said, I have had problems with it for not prewashing the fabrics, so I always prewash everything, except the batting (and I use primarily poly batting, but not the cheap stuff). I'm not trying to get rid of the crinkly look -- I just don't want to have asthma attacks because those can kill you. Another reason for prewashing, and my primary reason, is the bleeding dyes. That problem could ruin a quilt, so I don't chance it. I've had a lot of fabrics that did bleed, so I test them, treat them if necessary, and then use them, knowing they won't bleed after the dye has been set.