Which weighs more: 10 tablespoons of water or this ultralight down jacket? Answer: jacket. How do they shave the grams down to such a ridiculous sub-5-ounce weight? Let’s take a look.
|The 4.8-ounce MontBell Plasma 1000|
The new Plasma 1000 Jacket features (you guessed it) 1000-fill goose down, which you rarely see. As I understand it, this is the very upper fill power limit for natural goose down, at least according to the folks at the International Down and Feathers Laboratory, the nation’s leading test facility for down quality control, who I interviewed for an article on goose down’s amazing structure and properties. (As an interesting aside, Patagonia also recently unveiled lab-treated goose down that bumps up an 800-fill down to 1000-fill.)
Fill power is a measure of how many cubic inches an ounce of goose down takes up under standard laboratory testing conditions. A high fill-power down is thus warmer for its weight than a lower fill-power down. So this jacket, which features 1.6 ounces of down, should be just as warm as an equivalent 800-fill jacket with 2 ounces of down, for a savings of 0.4 ounce. (Or since we’re in gram-counting territory here, let’s use the larger grams-saved number: 11.3 grams.)
To add to this grams savings, the jacket also uses a ridiculously thin 7-denier nylon thread, which means that if you laid out 9 kilometers (~5.6 miles) of this thread, gathered it up, and put it on a scale, it would weigh all of 7 grams (0.25 ounce). This is also pushing the limits of what’s currently available on the market. (As with most ultralight fabrics, you’re making a trade-off here between weight and durability/abrasion resistance.)
Finally, the jacket does away with anything that might add extra grams. Its only “accessories” are a front zipper and elastic cuffs on the wrists. No pockets, drawstrings, Velcro closures, or anything else.
The total weight of the jacket (size medium) comes in at 4.8 ounces. As with all things ultralight, you pay more to get less, at least in terms of weight. And shaving down those final few grams often bumps up the price significantly. The Plasma 1000 Jacket retails for $269, or $56 per ounce. (If you stick to grams instead—$2/gram—perhaps you can better rationalize it.)
As for me, I’m always intrigued by the latest efforts to create the lightest-ever gear and I’ve always been impressed by the ultralight offerings from MontBell. And though the Plasma 1000 is interesting from a grams-saving perspective, the jacket I’ve got on my covet list is the MontBell U.L. Down Parka, which offers a lot more warmth for less price ($175, 9.0 ounces) and for less additional weight than another 10 tablespoons of water.
“Equipped” is an AMC Outdoors blog, written by Matt Heid.