Parachutes were known a long ago, yet from 18 century. However to beginning of Second world war of their dome made out of natural silk. Id est from fibres that is produced by the larva of silkworm. But a warring army needed many parachutes. How to reduce in price their production? Americans thought of to replace silk synthetic material - nylon. Now means of десантирования were no less durable, than before, but where more cheap. Another step was so done on a way to the epoch of synthetic materials.