Ultralight Pack Liners (Backpack Liner)The waterproof upgrade your expensive sleeping bag quilt deserves Most backpackers use a trash compactor bag or nylofume bags to keep their gear dry. It works until it doesn't. Trash bags or other thin plastic bags rip and tear over time, leak after a few weeks, fall apart in your pack, and turn into trash you have to pack out. Our Ultralight Pack Liner solves that, for the same trip count you'd cycle through 10+ trash bags, you get one liner that