Darlex

From Wipipedia

Darlex, sometimes sold under the trade name Darlexx, is a material similar to Spandex, but woven to be much thicker and hence more constricting and more opaque. It is thus ideal for a range of fetish and bondage garments, such as hobble skirts, cloth straitjackets and hoods.

(Safety warning: with hoods, breathing holes are advisable due to the thickness of the material.)