Waterproofing. A large rain can drench the forest floor and act similar to a sponge, wetting your tent if you setup in addition to it. The additional second layer of the footprint will blockade that rain from seeping upward into your tent, drenching your sleeping bag, clothes, and so on. https://wholesaletentmaterial09875.blogdun.com/30446382/5-essential-elements-for-tent-cloth