The MontBell Ex Light, as the name implies, is their lightest down jacket, with an average weight of 4.7 ounces for the women’s model (left) and 5.7 ounces for the men’s model (right). It’s insulated with 900 fill down, has a very thin 7 denier shell, and does not have any pockets.
MontBell states that the Ex Light Down Jacket is “the ultimate in minimalist design” and it's hard to argue with that. It combines cutting edge materials - 7 denier (0.74 oz/yd2) shell, 900 fill-power down - and minimizes features to create the lightest down jacket to be found. It’s claimed to provide more warmth than a fleece jacket with a fraction of the weight or bulk and is basically targeted to people like us who want a high warmth-to-weight ratio. So what's not to like? Is it truly a gift from heaven?
Front and rear views of the MontBell Ex Light Down Jacket in women’s size medium.
The outer shell fabric is 7 denier Ballistic Airlight nylon ripstop with a surface DWR finish. This 7 denier fabric weighs just 0.74 oz/syd2 (25 g/m2), which sets a new standard for a lightweight shell fabric. Ballistic Airlight has a very tight weave and is calendered, which is a heat and stretching process similar to tensiling steel. The resulting fabric (according to MontBell) has one-and-a-half times more abrasion resistance and three times more tear strength. Calendering also makes a fabric more downproof. On the downside, calendering reduces the breathability of the fabric somewhat.
While the shell fabric is very thin, it’s also very soft to the touch. It does not snag easily and is not damaged by Velcro. That said, we note that MontBell (on their hangtag) makes a point of saying: “Please be aware that this fabric will NOT fare well if exposed to sharp objects, high abrasion situations, or the occasional campfire spark. Going ultra-light comes with some inherent responsibility.” We commend MontBell for including this very appropriate message, and we fully agree with it.
The Ex Light has sewn-through construction. The women’s version has a quilted diamond pattern (left), while the men’s version has a rectangular quilted pattern. It has a full-height #3 zipper; the closures at the neck, cuffs, and hem are snug, but not tight.
Insulation is 900 fill-power down, which is the volume that 1 ounce (28 g) of down will expand to (900 cm³/g). This is the highest fill-power down presently available, and of course it is more expensive. The amount of down in a size medium MontBell Ex Light women’s jacket is 1.4 ounces (1.8 ounces in men’s medium). The actual amount of down in the jacket will depend on the jacket size. I measured the jacket’s two-layer (front and back together) loft at 1.25 inches, which means the single-layer loft is 0.6 inch. I held the jacket up to a bright light and observed that the down is uniformly distributed and is held in place by the jacket’s quilting.
I tested the Ex Light jacket while summer backpacking in the southern Rockies, while fall camping and hiking in the southern Utah canyon country and while cross-country skiing in the southern Rockies. I wore it as an outerlayer and midlayer in camp, in my sleeping bag, while hiking on cool or windy days and as an outerlayer when cross-country skiing. Temperatures ranged from 20 to 50 F (-7 to 10 C).
I normally wear petite sizing, and it’s always difficult to get a good fit with standard women’s sizing. Size medium usually fits me the best in order to get enough girth at the hips. The women’s medium fits me fairly well: the sleeves are a bit long, but I like the extra length to pull my hands up inside the sleeves. The body has a trim fit, but is not tight. The jacket extends down about six inches below my waist. There is enough room inside the jacket to wear it over a thick baselayer.
One problem I have had with the Ex Light Jacket, from day one, is that the zipper is very difficult to start. Rather than damage the zipper by forcing it, I wore the jacket as a pullover during the entire five-month test period. The problem seems to be a faulty zipper in my case, but it does emphasize the issue that ultralight garments are more fragile.
Another thing I discovered is that the women’s version of the Ex Light Jacket has less loft than the men’s version. As mentioned, the measured double-layer loft of the women’s size medium I tested is 1.25 inches. I measured the loft of my husband’s size large (2008 model) Ex Light Jacket at 2.0 inches. That’s a 37.5% difference! The fill weights are 1.4 ounces for the women’s jacket and 1.8 ounces for the men’s, which seems to be proportional to jacket size. When viewed side by side, men’s jacket is clearly loftier than the women’s. The reduced loft is likely due to the smaller quilting pattern in the women’s version, which may compress the down more. Personally, I would prefer to have a jacket with the loft of the men’s version, and I recommend that women interested in this jacket take a look at the men’s version first to see how well it fits. You will get a loftier jacket for the same price. I imagine however, that some women might prefer the slimmer look of a less lofty jacket.
To determine if the loft difference between the women’s and men’s versions significantly affects warmth, we conducted a “relative warmth” test (developed by subscriber Richard Nisley, which he posted in the Backpacking Light forums). We inserted a heating pad pre-heated to 105 F (41 C) into each jacket (back side up; room temperature at 60 F/16 C) and measured the surface temperature after one hour with an infrared thermometer (left). The surface temperature of the women’s version averaged 90.3 F (32 C), and the men’s averaged 67.6 F (20 C) (right). That’s a 25% difference, meaning the men’s version is significantly warmer than the women’s version of this jacket.
In my field testing, I did in fact find that the Ex Light provides more warmth than a fleece jacket, with a lot less weight and bulk, as MontBell claims. I wore the jacket as an outerlayer while hiking and carrying a pack on cool and windy days and found it to be very wind-resistant and warm. Abrasion from the shoulder straps of my backpack did not damage the thin shell. I found that it is not easily damaged from brush while hiking or skiing through branches, but I am always careful.
In camp, I wore the Ex Light as a midlayer most of the time. In the cooler temperatures I experienced in camp (33-45 F/1-7 C), I did not find the jacket warm enough by itself, so I normally wore another jacket over the Ex Light and sometimes a shell jacket over that.
I did not have an opportunity to test the Ex Light Jacket in rain or snow, so I tested it's water-resistance by placing a puddle of water on the shell for an hour (left), then checking for leakage. About half of the water soaked through the seams and collected on a tray inside the jacket (right). The fabric surface wetted out, and the down was wetted inside in the area surrounding the puddle.
I found that the jacket’s DWR finish repels water well, up to a point, but the fabric eventually wets out. Most of the water transmitted went through the seams and not the fabric.
The Ex Light comes with a stuff sack (0.3 ounce) made of the shell fabric, and it is properly sized for the jacket. The drawcord is longer and thicker than it needs to be, but that can easily be changed.
There are no other down jackets available as light as the MontBell Ex Light. The following table compares the Ex Light to the lightest down jackets from other manufacturers. For comparison, the listed specifications are manufacturer data for a men’s size medium (or unisex medium). All jackets have sewn-through construction except the Nunatak Skaha, which is baffled.
|Jacket||Shell Fabric||Fill Power||Measured Single-Layer Loft (in)||Features||Weight (oz)
|MontBell Ex Light||Ballistic Airlight
|900||1.0||Full zip, elastic cuffs and hem||5.7||165|
|MontBell Down Inner||Ballistic Airlight
|800||0.85||Full zip, two side pockets, elastic cuffs and hem||7.3||150|
|PHD Ultra Down Pullover||MX Microfiber
|900||1.3||Half zip, reach-through front pocket, zippered security pocket, elastic cuffs and hem||8.0||~284|
|Nunatak Skaha Pullover||Pertex Quantum
|850+||2.0||Half zip, baffled construction, drawcord hem, elastic cuffs||9.0||319|
|Western Mountaineering Flash||Dot-Ripstop Nylon
|850+||0.9||Full zip, hood, two side pockets, elastic cuffs and hem||9.0||260|
The closest competition is MontBell’s own Down Inner Jacket, which weighs 1.6 ounces more and costs $15 less. The Down Inner Jacket has a more durable 15 denier shell, less lofty 800 fill down, and two hand pockets. A parka version is also available. The Ex Light Jacket is made of cutting-edge materials (900 fill down and 7 denier fabric), and is nearly devoid of features, so you are paying more for the lower weight.
The MontBell Ex Light Down Jacket is truly in a class of its own - the lightest down jacket available. Its only close competition is the MontBell Down Inner Jacket and Parka. For hikers wanting hand pockets, the Down Inner Jacket adds them at a modest weight increase, and the Parka version adds a hood.
Nevertheless, I am not totally happy with the lower loft and warmth of the women’s version of this jacket compared to the men’s version. I went down to a local outdoor store and measured the loft of the Ex Lite Jacket there to verify my home measurements and found the same difference. I also compared the men’s and women’s version of the MontBell Down Inner Jacket and found that the women’s jacket has 30% less loft. The women’s version of many lightweight down jackets has more quilting to make it more stylish, and also to give the jacket a lower profile (news flash: women don’t like to look fat, or even puffy). While some readers argue that slightly compressed down insulates better than fully expanded down, the extra quilting on the women’s version of many down jackets seems to go beyond that. Why should men get a loftier/warmer jacket, for the same price? Seems like the reverse ought to be the case! I may be in the minority in my thinking though, because I value warmth more than style.
Overall, I am very impressed with the amount of warmth the Ex Light Jacket provides for its miniscule weight, as well as its versatility. While many down jackets are simply too warm to wear while hiking uphill, the Ex Light is more comfortable on the trail, and it cuts the wind very well. If it gets colder or windier, a shell over it is usually enough.
Specifications and Features
|Year/Model||2009 Ex Light Down Jacket|
|Style||Full zip jacket|
|Fabrics||7 denier Ballistic Airlight 0.74 oz/yd2 (25 g/m2)|
|Insulation||900 fill-power down|
|Construction||Sewn through with 2.5-in (6-cm) diamond quilting (women’s), 3.25 x 4.25 in (8 x 11 cm) rectangular quilting (men’s)|
|Loft||Measured two-layer loft 1 in (2.5 cm)|
|Features||Down filled stand up collar, full height front #3 YKK zipper with one slider and storm flap under zipper, elastic cuffs, simple sewn hem (not elastic), stuff sack included|
||Measured weight, women's medium tested: 4.2 oz (119 g)
Manufacturer specified average weight: women’s 4.7 oz (133 g), men’s 5.7 oz (162 g)
Disclosure: The manufacturer provided this product to the author and/or Backpacking Light at no charge, and it is owned by the author/BPL. The author/Backpacking Light has no obligation to review this product to the manufacturer under the terms of this agreement.