Rectangular Sleeping Bags: I got into Wiggy's bags because mummy bags drive me crazy, and these have some room. The bags, like all Wiggy's stuff, are based on his own insulation, which he calls Lamilite. It's a continuous-fiber material that can be crushed, unmercifully, for years on end, and doesn't care, and whose every strand is waterproof. This means it won't absorb moisture, period. Gunny Newman, on a cold night, once got into a Wiggy bag, jumped into a swimming pool, got out, shook the bag a couple of times, and was perfectly warm. Gunny Newman does stuff like this.