Silnylon, a portmanteau of "silicone" and "nylon", is a synthetic fabric used mainly in lightweight outdoor gear. It is made by impregnating a thin woven nylon fabric with liquid silicone from both sides. This makes it strong for its weight, as the silicone substantially improves the tear strength. It is also highly waterproof, but not breathable. Many colours are available.
Several types of Silnylon are produced. The common type is a quiet, silky, very slippery fabric. The variant known as "crisp silnylon" is lighter, but brittle, noisy, and tears easily. Some versions are made from the stronger type 66 nylon and are used for applications like parachutes and hot air balloons. Some use a blend of silicone and urethane which is done partly to reduce the air pollution during manufacture as it reduces the aromatic solvents used in the coating process.