I read a while back that goretex bivi bags, and by extension I presume goretex products in general, should be stuffed in a stuff-sack and never folded/rolled up as apprantly goretex does not like to be folded in a predictable way for any length of time. It sounded a little unfounded to me, but considering how expensive our goretex kit is, I would love to know for sure if this has any truth to it as I currently store my army issue bivi bag tightly rolled up secured with a rubber band.