UltraTenX is about as much strength as you can get into 99 grams per square metre. Challenge Sailcloth builds it by laminating a woven UHMWPE face to a ±55° UHMWPE crossply and a PET film, so the load paths run in four directions instead of two. The result is a fabric that shrugs off tear propagation, holds over 50,000 mm of water column, and weighs less than most 200D nylons. The ±55° crossply is the part that matters. That's why the warp tensile lands at 385 lbf/in while the weft still holds 245. It sews cleanly with a sharp needle and a bonded polyester thread. Like any film laminate, it's waterproof through the face but not through your stitch holes, so tape or seal the seams on anything that needs to stay dry. Best for ultralight packs, dry bags, stuff sacks, bikepacking bags, and any panel where you want strength without the weight penalty. Available in Jet Black and Pink, sold by the half yard. Order a sample if you want to feel the hand before committing. Specifications Composition 50% Polyethylene, 26% Polyurethane, 24% Polyester Weight 99 gsm (2.9 oz/yd²) Width 58 in / 147 cm Weave type Plain weave Colours Jet Black, Pink Sold as Per half yard, cut continuous Country of origin China Construction Face UHMWPE woven fabric Reinforcement ±55° UHMWPE crossply Backing PET film Laminate type Film laminate Tapeable Yes, with UltraTNT PSA Tape Performance Tensile strength (warp/weft) 385 / 245 lbf/in (1712 / 1090 N/2.5cm), ASTM D3039 Tear strength (warp/weft) 197 / 103 lbf (877 / 458 N), Mil-C-21189 Water resistance Over 50,000 mm H₂O, ISO 811:2018 Key features Lightweight, high strength, waterproof Best for Ultralight packs, dry bags, stuff sacks, bikepacking bags
