The Gossamer Gear Polycryo (aka polycro) Ground Cloth, for its weight, is the most durable material we’ve ever used. It stays water- and puncture-resistant and we recommend it for even the wettest environments. It’s easy to repair with Tyvek tape. Far more durable than a mylar space blanket, and just as light. The stock size (“large”) is enormous – 72 x 96 in (183 x 244 cm) – by the time you cut one down for solo use (e.g., 72 x 24 in / 183 x 61 cm), you have a ground cloth that weighs only 0.9 oz (26 g).