Aircraft fabric covering often used in the restoration of older types that were originally covered using traditional methods. The purposes of the fabric covering of an aircraft are: Pioneering aviators such as George Cayley and Otto Lilienthal used cotton-covered flying surfaces for their manned glider designs. The Wright brothers also used cotton to cover their Wright Flyer. Other early aircraft used a variety of fabrics, silk and linen being commonly used. Some early aircraft, such as A.V. Roe's first machines, even used paper as a covering material. Until the development of cellulose based dope in 1911 a variety of methods of finishing the
Waterproof fabric Standard laboratory testing protocols define the performance of these fabrics. Water resistance is measured by the amount of water, in mm, which can be suspended above the fabric before water seeps through. Breathability or Moisture vapor transmission rate is measured by the rate at which water vapor passes through, in grams of water vapour per square meter of fabric per 24-hour period (g/m/d), often abbreviated to just "g". In recent years some, but not all, sporting goods manufacturers have begun including this information on their product labels. Typical mid-range fabrics tend to have values of 5,000 mm of water resistance