Are there any waterproof or close to waterproof materials that are adequately breathable for a bivy or a tent? There seems to be a trade-off between breathability and waterproofness. The more waterproof a material is the more it condenses moisture from what I understand. The only possible exception to this rule that I’ve seen is the claim made by Outdoorresearch about their bivy sacks. Are the Outdorreasearch bivies really breathable and waterproof or close to waterproof? Is the 3 layer GORE-TEX used by Outdoorresearch the only breathable and waterproof material? How expensive are they? Thanks for any replies.