GORE Tenara is an ePTFE (expanded polytetrafluoroethylene) sewing thread engineered for permanent outdoor and marine applications. The fiber is pigmented rather than dyed, giving it complete UV immunity and lifetime colorfastness. Unaffected by saltwater, chemicals, bleach, mildew, and extreme temperatures. Carries a manufacturer guarantee to outlast the fabric in which it is sewn. Designed for awnings, biminis, boat covers, sail covers, and architectural fabric structures.