Sorry, My error. I understood their page to say that the felt the taffeta was more water resistant than the ripstop because of the more uniform surface texture. But they were comparing it to Pertex ripstop... which they say is very similar but not as water resistant. Yet the really high end sleeping bag companies use the Pertex on their $400 plus sleeping bags. If Momentum is as good or better then its probably pretty darn good..
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