Everything in the Western Mountaineering HighLite's design is intended to reduce weight and promote compressibility. First, the .9 ounce ExtremeLite shell fabric goes without saying. No other shell fabric is this light or packed with so many threads per inch. While the horizontal seams are sewn thru, the vertical seams are baffled with 1 12 inch netting to allow unimpeded loft so the effect of its 850 goose down is fully realized. Its efficient cut not only reduces bulk and weight, but reduces excess internal volume so quick heating is realized! At only 16 ounces total weight, no other bag is as light, as warm, as well made or as handsome as the HighLite.