Parachute canopies have to withstand high wind pressures, especially when operating at altitude, and nylon is a common choice of material in the manufacture of canopies. Nylon is completely windproof and has the added benefits of being lightweight, readily sourced and inexpensive. The strength, flexibility and light weight of nylon also make it ideal as the material used in the straps of the parachute harness.
Some parachutes canopies are being made from a newer material, Kevlar. A major benefit of Kevlar is its extreme strength, which means it is used in the manufacture of bullet-proof clothing. Kevlar, like nylon, is a man-made fiber. It is highly resistant to heat, making it flame-resistant, and does not lose its strength and shape at high temperatures. Kevlar parachutes maintain their tensile strength well even when left folded for extended periods, as was found during tests done for the U.S. Department of Energy.
Early parachutes canopies were made of canvas, but silk was later utilized because it is thinner, better resistant to wind, resistant to fire and much easier to fold. Silk was used as early as the 1790s when parachute pioneer Jean-Pierre Blanchard began to make parachute canopies out of the fabric. Silk remained a popular material in parachute manufacture up until World War II, when silk imports became expensive and difficult to obtain, leading to the development of nylon parachute canopies