Until recently, replenishing 1,000 was a rare commodity. Jackets that contained it were always rare. But this year there will be more than normal, giving weight new options for ultra-packable warmth. Don’t be too excited though: quantities will be limited and prices will be high compared to what we are used to. Mountain Hardwear, for example, initially only made 2,000 of its flagship Ghost Whisperer UL ($ 375), while you can likely get the best-selling 800-fill version and $ 50 less. Is the extra fill power and two ounce weight saving really worth it for hunting?
Calculating the fill power is a helpful method for assessing the weight-warmth ratio of various down jackets. Fill power is a measure of the quality of the down and the approximate volume in cubic inches of an ounce of down. So an ounce of 650 fill takes up approximately 650 cubic inches of space, an ounce of 850 fill is 850 cubic inches, and so on. It is important to note that fill power does not necessarily correspond to heat. The numbers mean this: Since the volume of 1,000 fillings is high, it is not as dense as other fillings and offers more space to trap air in the plumage. A jacket with 650 fillings takes up less volume than a jacket with 1,000 fillings, so it is denser and offers less space for warm air. But when it comes to warmth, how much of it is stuffed into the jacket really matters.
We’re going to use Mountain Hardwear’s Ghost Whisperer UL as an example. This jacket has two ounces of down with 1,000 fillings (this important measurement is often given on the product page along with the total weight of many jackets, although not every brand lists it) which means the volume of the down is approximately 2,000 cubic inches. Remember that heat is tied to volume. A jacket with 800 cubic inch down filling should be about as warm as an otherwise identical jacket with 2,000 cubic inch down filling 1000 like the Ghost Whisperer UL – the 1000 filling is only lighter.
But how much easier? With a little high school algebra, we can work backwards and share the Ghost UL’s 2,000 Fill cubic inches of down by 1,000 to determine that the down weighs two ounces. How does that compare to a jacket with 800 fillings? The same 2,000 cubic inches (which means the jacket is just as warm) divided by 800 fill makes 2.5 ounces. Even a 650-fill jacket with the same warmth weighs only three ounces. For smaller jackets, the 1,000 to 850 weight difference can be minimal, although the difference can be greater for products such as sleeping bags that use tens of thousands of cubic inches of down.
While the fill power definitely saves ounces for those looking to slim down their kit, the weight difference is small for many jackets, and real weight savings will likely come from everything related to down. If manufacturers spend a lot of money filling their jackets with 1,000, it’s likely because they’re trying to make them super light. That said, they will also try to keep the weight of the fabrics, zippers, and other features to a minimum. However, if weight is less important, they can improve durability and function and use cheaper down.
How I tested
I rucksacked these jackets in the west between fall 2019 and summer 2020, ice climbing and skiing in the backcountry. Temperatures ranged from the low fifties to bitter single-digit numbers below zero. Given the variety of jackets and their different warmth, each generally fell within its own optimal activity and temperature ranges. (The latter is a subjective assessment based on my body, what I was wearing with the jackets, and the activity of the day.)
Mountain Hardwear Ghost Whisperer UL ($ 375)
(Photo: Ryan Wichelns)
Best for: Nerds obsessed with ultra-light technology
Weight: 6.7 ounces (men’s medium)
Down Weight: 2 ounces
Optimal temperature range: 50 to 35 degrees Fahrenheit
At this weight, there may never have been a down jacket with more functions – or at least I haven’t seen one yet. Mainly thanks to the featherweight The Ghost Whisperer line is a nylon outer fabric (or an outer layer) that gives the jacket its name. She has been able to claim this title for some time. However, the latest version of the brand swaps 800-Fill-Down for the Primo-1000-Fill and replaces ultra-light 10-denier outer fabrics with an almost paper-light 5-denier version, whereby the weight of the Ghost Whisperer UL corresponds to that of a billiard ball.
That slight warmth was enough to ease those off-season summits or breakfast on backpacking summer trips in the Beartooth Mountains of Montana when temperatures were in the low-fifties. It’s a delicious midlayer in the colder months (fits great under a ski bowl), but on cool ski touring trips, it probably won’t be my only swelling (adding a parka would be nice for cold transitions). And at this heat level, the difference between the UL and the 8.8 ounce version with 800 fillings is really only noticed by picky ounce counters. Cost aside, the weight savings can be well worth the paranoia of brushing this jacket against a branch. I babysat mine and still saw a few small ticks while cutting the bush.
Buy Men Buy Women
Eddie Bauer Centennial Collection MicroTherm 1000 ($ 399)
(Photo: Ryan Wichelns)
Best for: Move while bundled
Weight: 9.6 ounces (men’s medium)
Down Weight: 3.2 ounces
Optimal temperature range: 50 to 30 degrees Fahrenheit
The MicroTherm 1000 only offers a little more than an ounce of additional down compared to the Ghost UL, but Eddie Bauer took few risks on the outer fabric with a tough (for this category) 20 denier material. Stretchable fleece inserts under the arms increase flexibility and breathability.
This jacket held me slightly warmer than the Ghost Whisperer. I felt comfortable in my high forties without moving. The armpit plates didn’t seem to detract from the warmth, but were a welcome feature when moving above the tree line during the fall hikes of Bear Peak in Boulder, Colorado, with early morning temperatures in the high forties. The outer fabric still deserves some caution with sharp objects, but I was confident of putting it in my backpack or carrying it while I went over and around the blow off.
Buy Men Buy Women
Mont Bell Plasma 1000 ($ 439)
(Photo: Ryan Wichelns)
Best for: Backpacking trips in the shoulder season
Weight: 8.4 ounces (men’s medium)
Down Weight: 3.4 ounces
Optimal temperature range: 45 to 25 degrees Fahrenheit
While The down weight of the Mont Bell is similar to that of Eddie Bauer. The baffle design of the Plasma 1000 stacks the down a little thicker and makes it noticeably more puffy and warmer than the jackets from Mountain Hardwear or Eddie Bauer. It was my first choice for winter backpacking in the desert: I took Little Death Hollow to the Escalante River in Utah, where morning temperatures didn’t go beyond the high thirties. It was also a comfortable jacket for ski transitions on days when the mercury dropped to the low thirties. The 7-denier outer fabric feels a little wrinkled and light, and was just as delicate as the Ghost Whisperer’s – I put the cuff over a rough boulder as I hiked down the Escalante and made a small tear – but this Heat to weight ratio of the plasma is almost the best of the jackets I have tested. The whole thing is slightly smaller than a 32-ounce nalgene.
Rab Zero G ($ 550)
(Photo: Ryan Wichelns)
Best for: Super cold adventures
Weight: 10 ounces (men’s medium)
Down Weight: 4.05 ounces
Optimal temperature range: 35 to 15 degrees Fahrenheit
With larger puffies like Rabs Zero G, the 1,000 fill-down value becomes more apparent. With extra down on the inside (more than double the down on the Ghost Whisperer is used) the weight difference between a similarly warm, 800 fill jacket could be much more obvious. The Zero G was warm enough as an ice climbing safety jacket or as a puffy for the winter backpack on the Hyalite Canyon in Montana. The downside, however, is that an extra 1,000 fill makes this the most expensive jacket I’ve tested – at over $ 110.
The Zero G quickly became my favorite winter puffy on days when the digits were well below freezing. Thanks to a 10-denier outer fabric, it remained surprisingly intact (I made a small incision in the body with a faulty ice screw in my backpack), although it found more use than any of its competitors.
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Main photo: Ryan Wichelns