Nylon stocking fibres. Coloured scanning electron micrograph (SEM) of the weave of a nylon stocking. Nylon is a polyamide substance, and was the first synthetic fibre ever to be produced. Nylon fibres are stronger and more elastic than silk and are relatively insensitive to moisture and mildew. Nylon is extensively used to make textiles, but is also used in moulded articles and medical sutures. Magnification unknown.