Waterproofing and breathability of fabrics and garments. L. Hunter, J. Fan, in Engineering Apparel Fabrics and Garments, 2009 Micro-porous membranes and coatings. Micro-porous membranes are generally made from the polymers 27 PTFE, polyurethane (PU), polyolefins, polyamides, polyester, polyether and polyether based copolymers, with the first two mentioned (i.e. PTFE and PU) being the most popular.