Want to know what's so special about The North Face's new mountaineering jacket? Just look at the name. The Fuse Uno is made from just one piece of material. By fusing fabrics of different strengths together during the weaving process, the company has created a jacket with varying levels of durability and utility, and it's done so almost entirely without seams.

This is a big step forward in technical garment design. Normally, outerwear like shells and jackets require different fabrics to be stitched together in order to give them the variable levels of durability they need. For example, the shoulders on a mountaineering jacket are typically built from a stronger fabric because they come into contact with backpacks, skis, and other equipment. The torso material, however, doesn't need to be so tough.

The principal drawback to using multiple materials is that more stitching is needed, which adds seams that can wear out and potentially let water in. Mixing and matching fabric types almost always adds weight, as well.

To build their one-piece jacket, the garment-makers at The North Face simply changed the yarn as they wove the sheet of material. The upper section is made from a 40-denier yarn mixed with Cordura, which adds strength. The lower section is 40-denier yarn as well, but doesn't have the Cordura. The most complicated problem, it turns out, was figuring out how to cut the entire jacket from that single piece of material. Designers spent years building an origami-like pattern that would fold together and require minimal stitching.

What they finally came up with was a jacket that reduces the seams by more than 40 percent compared to a similar piece of apparel like The North Face Hyalite jacket. The Fuse Uno still protects the wearer from the nastiest conditions, and it weighs just 12.3 ounces (350 grams) for a men's size medium.

The North Face people I interviewed wouldn't say what's next, but they're eager about this technique's potential. In addition to materials with variable durability, the company could also weave sheets of material that have variable breathability and/or stretch, which are also important elements in outerwear design.