There’s no perfect insulation. Whether you’re looking for a jacket or a sleeping bag, you’ve likelyencounteredthe trade-offs between down and synthetics. Downis extremely warm for its weightand compressesto take up very little space in a pack. But the feathers clump and are useless when wet, and they tend to spill out if the shell material tears, making field repairs tricky. Synthetic fills, which are madeinsheets rather thanindividual fibers, retain warmth when wet and stay in place when the outer fabrictears. But they’re heavier than down and don’t pack down nearly as well.
Nemo may have come up with a solution. The company’s new ($200 and up) features a new synthetic-insulation construction called FeatherCore, which, according to Nemo, is as light and compressible as 650-fill-power down. (For reference, 650 fill fallsinthe middle of the down spectrum with regard to packability: top-level products have 800-fill down, which is as warm as 650 but weighs less and packs smaller, while low-end products have 500-fill down, which is far heavier for the same warmth.) FeatherCore consists of regular PrimaLoft Silverinsulation that’s manipulated to reduce weight and bulk. Nemo says the technology is proprietary and did notgo into specifics on exactly how itmade the existing synthetic fill so much lighter.
Having spent too many mornings wrangling stubborn synthetic bags into their stuffsacks, I was dubious. But after getting my hands on the 20-degree Azura, I’mconvinced that Nemo is onto something. The bag stuffs down into a package a little bigger than a loaf of sandwich bread and weighs 2.6 pounds. Most other 20-degree synthetic bags weigh three pounds or more. (The Azura comes in 20- and 35-degrees versions, and in regular and long lengths. The men’s version, called the Kyan, comes in the same specs.)
Weight aside, the Azura features a 20-denier ripstop outer, nylon taffeta on the insidefor a soft next-to-skin feeling, and Nemo’s trademark zippered vents along the top, called gills. I haven’t had the chance to use the Azura out in the wild yet. But the prospect of a sleeping bag that offers the versatility of synthetic insulation without completely sacrificing on weight and bulk seems like a win in my book.