Preview: Western Mountaineering Nanolite & Astralite || Premium UL quilts

Western Mountaineering enters the quilt category in spring 2018 with the 38-deg Nanolite and 26-degree Astralite.

Western Mountaineering is known for not chasing trends and for being supremely loyal to its retailers. So the news that it’s offering a sleeping quilt for spring 2018 says two things to me:

  1. Quilts are not a fad, and have perhaps reached critical mass; and,
  2. WM retailers became convinced — by either a compelling WM pitch or, more likely, customer inquiries — that there is a market for quilts.

Western’s new quilt is, of course, a beautiful product that is made of premium materials (notably, 850+ European down and 7d & 10d fabrics) and that appears masterfully constructed. You don’t expect less of WM. The quilt is available in two temperature ratings in two sizes (up to 6’0″ and 6’6″):

  • Nanolite ($330, 11 oz), rated to 38 degrees F
  • Astralite ($400, 16 oz), rated to 26 degrees F

The quilts were not EN tested, but WM ratings are considered among the most conservative.

The “passive top collar” is contoured in such a way as to reduce drafts around the neck, especially when cinched.


The Nanolite and Astralite have the same 850+ fill power European down that is used in all WM products, including apparel like its lovely Hooded Flash Jacket and Flash Pants. It’s a time-tested commodity, and I’d be skeptical to believe that any familiar brand is using high quality down, including those that claim 900 fp. WM continues to use untreated down, believing that the large clusters and natural oils in its down offer sufficient resistance to moisture.

The shell fabric is a proprietary 7d with an acrylic kiss coating for added durability. WM had it milled specifically for these quilts, but may begin to use it in other products once they have more long-term feedback. The liner is a 10d taffeta.


The quilt’s dimensions are based on the Western Mountaineering Ultralight, which John from WM described as being a “performance cut mummy bag.” It specs at 59 inches at the shoulder, 51 inches at the hip, and 38 inches at the footbox; the larger size is one inch wider at the shoulder and hip.

The footbox is sewn closed, eliminating the option of opening the Nanolite or Astralite into a rectangular quilt.

Sewn footbox

The back closure system on their sample bags at Outdoor Retailer was a rat’s nest of bungee cord, but I was told that production would have three strips of 1/2- or 3/4-inch grosgrain webbing, probably similar to those on the Enlightened Equipment quilts.

As I watched John squirm into a quilt that was attached to a pad, I questioned this feature. Personally, I remove the attachment system, because I don’t like feeling as if I’m strapped to a backboard. And if I want a draft-free sleeping experience, I know of a much less fussy way to get it. It’s called a mummy bag.

The most interesting design feature is the contoured “passive neck collar” that can be cinched with an exterior bungee cord in order to minimize drafts around the neck. The seal did not appear as effective as, say, the hide-away hood on the Sierra Designs Backcountry Quilt, but the comparably rated Nanolite is less than half the weight of the BCQ.

Especially when cinched, the contoured top color will help to reduce drafts around the neck. But it still does not seal as well as a mummy or hide-away hood.


How do the Astralite and Nanolite stack up against other premium quilts from cottage brands like EE, Katabatic, and ZPacks? In terms of features and materials, they didn’t strike me as being exceptionally better or different. And the WM quilts seem more expensive versus quilts of comparable warmth and size, which may be directly attributable to the additional “middle man” mark-up.

But it may not matter. WM sells only to retailers, not direct, so customers that want to support their local retailer or who want to try before they buy will be limited to the WM quilts.

Questions about the Nanolite or Astralite? Leave a comment.

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  1. Eli on January 31, 2018 at 10:05 am

    Any idea on loft specs for these quilts? It would be nice to compare them all on a level playing field rather than speculating based on fill weight or the manufacturer temp rating.

    • Andrew Skurka on January 31, 2018 at 10:51 am

      The loft was not specified on the spec sheet, sorry. And these products are not yet up on the WM website.

  2. Dan Durston on January 31, 2018 at 12:35 pm

    Very interesting. Having WM move into this market does lend quilts more credibility.

    The 6.5oz of down in the 38F quilt seems a bit low, with EE and Katabatic putting 7.7 – 7.8oz in their 40F quilts. Will R. reported the regular length of the WM quilts to be too short for this 6′ body, so maybe the weight and fill is lower because they aren’t quite as long, or slimmer.

    The WM quilts look like a no brainer over the similarly priced Zpacks quilts. I’ve opened up Zpacks quilts and been quite unimpressed with their feather filled “900” down, and WM quality is light years ahead. I’d happily pay a little more for WM here.

    Most folks will be best served by EE and UGQ, but I see WM and Katabatic duking it out for the premium market. Do the WM quilts have a differential cut like Katabatic?

    I’m with you on shunning the attachment systems. I use attachment system free quilts when it’s not super cold (>20F) and then go to mummy bags below that.

  3. Hunter G Hall on January 31, 2018 at 1:58 pm

    I figured they would enter the market eventually. Curious if they will ever add synthetics to their arsenal to make the bags more versatile…

    Unless they offer customization like ZPacks and EE, I don’t see nitpicky people like me buying them.

    Personally, I love ZPacks gear, including the quilts, and have no issues. Fast, direct, custom, etc.

    Still waiting for some genius to solve the draft problem with quilts sans straps.

  4. Edward on January 31, 2018 at 9:04 pm

    Hrm… my Feathered Friends Flicker quilt weighs more, but has a full zipper, so no Houdini contortions necessary, no drafts, and the full unzip to a quilt makes it so versatile I’ve been using it at home thus vastly increasing the bang-for-buck rating.

    Love my Western Mountaineering Summerlite and Ultralite, but not a fan of the drafty quilt strap setups from any purveyor.

  5. Jay on January 31, 2018 at 11:49 pm

    These look pretty amazing. I’ve always gawked at WM stuff, but nothing more than gawking. The prices make sense. Yes you can get cheaper stuff from any number of places, and I think my Hammock Gear quilts are fine for me, but they’re definitely not perfect like the WM stuff I’ve seen is.

    And I think they’re in the right temp range. A quilt at a lower temp rating doesn’t really make much sense.

    Last week I was up in the mountains here in Arizona and it was down around 15 or 20, and I had a 30 degree quilt, a 50 degree quilt, and I was in a borah gear bivy (really helps keep drafts to a minimum, so I take it even when bugs aren’t a concern), and I was more than fine. I have a sleeping pad attachment setup, but I used it once and found it to be enough of a tangle that I never bother anymore. I was plenty warm last week, but I don’t think I’d push my quilt setup below 15 or so, and even at that, I’d have probably been more comfortable in a decent mummy. At least it’d have been a single piece! That said, the quilts and bivy together weigh less than 40 oz, and I don’t own a warm mummy and don’t plan to buy one because I live in Arizona, but I’d probably have to rethink that if I was going somewhere really truly cold at night for more than a couple nights.

  6. PS on February 1, 2018 at 11:13 am

    I don’t understand the whole mummy bag shape but its a quilt? I like my Nemo tango. It’s a couple years old and a bit heavier but I only use it with an insulated air pad and it give me plenty of room to toss & turn as I always do. If its so cold that I need a tight, heavy fill mummy then I probably don’t really want to be camping anyway.

  7. Gordon on February 2, 2018 at 9:42 pm

    Hammock Gear Burrow 30°: 9 oz fill weight (15.75 oz total), 850 fill power, $252 with sewn foot box. Just sayin’.

  8. Jeff McWilliams on February 6, 2018 at 2:51 pm

    I’m a “rotisserie sleeper”, aka I toss and turn all night due to lower back issues. Even at home on an expensive memory foam mattress, I move around a lot.

    I find the strap & clip attachment system on my Enlightened Equipment to be great I can toss and turn while the sides of the quilt remain pinned to my NeoAir pad.

    Getting in and out is as easy as popping two clips on one side of the quilt and sliding my legs out from the lower part of the quilt.

    I’ll never go back to a mummy bag after getting my quilt figured out. It may be a bit colder for a given rating than an equivalent bag, but I prefer not feeling claustrophobic.

    • Andrew Skurka on February 6, 2018 at 4:44 pm

      Have you tried a top bag? The attachment system has much less fuss, and most allow easier entry/exit via a side or center zipper (versus the slither required in a quilt). I’m a pretty calm sleeper, but even I developed an appreciation for the system after using a top bag for 1.5 weeks last summer.

  9. Jeff McWilliams on February 6, 2018 at 7:21 pm

    I followed your link to Therm-a-Rest site and am looking at the 20 degree Parsec bag, and I’m not sure I get it.

    It’s a mummy bag that has sleeping pad attachments, with 60% of the down fill concentrated on the top baffles, and 40% on the bottom.

    What is “Thermacapture lining” is supposed to be? Is it a non-breathable fabric? Some sort of reflective lining like Columbia’s “Omni-Heat”? What?

    And “Toe-asis foot warmer pocket” just sounds like fancy marketing fluff to describe an insulated foot box.

    My concern with this design is this: It’s still a mummy bag. If I climb inside that thing and attach it to a pad, when i roll, I will roll inside the mummy bag while the bag remains stationary. My face will now be stuck partly inside the hood. 🙁

    • Andrew Skurka on February 7, 2018 at 4:06 am

      Just to be clear, I’m not recommending these bags, just suggesting them as a top bag option.

      With 40 percent of the down underneath, they seem to undermine the top bag concept, which is to use no insulation underneath and to rely solely on the sleeping pad. But I digress…

      In regards to your concern, yes, with a top bag you will roll around inside the bag, while the bag stays put. It’s like the sheets on your bed at home — you move, and the sheets (mostly) stay on top of you. Yes, you may get twisted inside the bag, but at least you’ll always know that the hood opening is up. Also, unless you’re pushing the limits of the bag, you don’t necessarily need to have yourself sealed tightly into the hood — the opening can be kept loose.

  10. Bruce G Williams on April 3, 2019 at 7:04 pm

    Andrew, I am curious about the sizing. I am 6′-0″ and I was thinking about the regular but being that the bag is only 5′-8″ I am concerned that it won’t be long enough. What are your experiences?

    • Andrew Skurka on April 8, 2019 at 9:22 am

      It’s taken Western a little while to decide how to size these bags, or, actually, how to explain the sizing.

      My demo version was described to me by Western as being 6’0″. I assume it’s the version they now describe as being 6’4″, since its weight specs are more consistent with that size and since I have a few inches to spare inside of it. BTW, I’m 6’0″.

      The best thing to do is call them. They CS should be excellent, and they can very quickly give you an answer on this.

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