Polyamide is a synthetic fibre highly resistant to friction (about 10 times greater than cotton and 20 times more than wool). The polyamide fibre is very stretchy and static charge-resistant. It is lightweight, almost impermeable to water, non-creasing, and durable. Polyamide is not flame-resistant and melts when burning. Thus, it is often mixed with natural fibres, increasing their durability and life. Non-rinsing products should be used for washing. The most popular type of polyamide is nylon.