Tarp is the shortened name for a tarpaulin, which is a general term for a water resistant sheet of fabric that can be used as a ground covering, shelter from rain or wind, or to wrap up your possessions for protection. Backpacking tarps can help backpackers save weight over a tent and can be very flexible as they can be pitched in many different configurations depending on their size and the coverage need at hand. Tarps come in many different shapes and sizes and are usually made from nylon, polyester or cuben fiber. Silnylon is heavier than cuben fiber but cheaper and stretches when wet. Cuben fiber has an extremely high strength-to-weight ratio, which makes it a great tarp material and does not stretch like nylon does.