• Midweight hybrid jacket with ThermoBall™ insulation and stretch panels
• ThermoBall™ powered by PrimaLoft® synthetic insulated body retains loft and warmth, even when wet
• 30D Nylon stretch taffeta with DWR finish
• Molded-tooth front zip

• Internal elastic cuffs
• Secure-zip covered hand pockets
• Stowable in hand pocket
• Hem cinch-cord
• Average weight: 18.4oz
• MSRP: $220

Stretch it out

The North Face’s Thermoball insulation became big news just a few years ago, thanks in part to the oomph of PrimaLoft’s excellent reputation and the promise to differentiate itself from other synthetic insulations. It’s telling, too, that the description for Thermoball starts off with “Unlike other synthetic insulations…” This is a technology that’s seeking to differentiate itself.

Thermoball’s difference lies very deep down at the form given to the insulating structure itself. Other excellent synthetic insulations rely on more-or-less continuous threads to weave together a sheet of fluffy warm fabric that’s then stitched into the panels of a jacket. By contrast, Thermoball is just that – balls. Balls and balls of individual bits of insulation add up to mimic the space-creating function of traditional goose down puffballs.

This means that there are plenty of differences between Thermoball and other synthetic insulations. For one, Thermoball doesn’t come in a sheet; instead it’s something to fill baffles, like traditional goose down. Because the insulation is made of individual balls of compressible fabric, a Thermoball jacket likely compresses better than a similar jacket with traditional fabric sheet insulation.

So why would you buy something that mimics down so closely? Well, there are basically two reasons. The first is that Thermoballs’ wet-weather insulation is excellent. I’ll talk about this more in the review. The second reason is that it’s much more affordable than goose down insulation.

Two hand pocket zippers can sometimes snag

My testing for the Stretch Thermoball took me from the wet Pacific Northwest ski slopes to the frigid, dry Nevada high dessert. I don’t usually go in for artificial tests or forced circumstances, but I wanted to see just how well the jacket did when really pushed. So, I took a leaf out of Gear Junkie’s testing book and then I ramped it up two notches. Instead of a dunk test in 30 degree weather, mine would be a dunk-squish-sponge-absorb test in 20 degree weather. And that’s what I did – I wanted to see what it would take to saturate the jacket and then how it would perform once I pulled it on and got moving.

I was very impressed with how the jacket handled the moisture. The DWR on the 30D nylon did an excellent job repelling water and, but we all know that DWRs don’t last forever. What really impressed me was how little water the Thermoball absorbed when I squished the jacket like a sponge to absorb water. The synthetic fibers absorbed scarcely any water at all and each individual baffle retained its loft. When I pulled it onto my shivering body and got moving, it warmed up and dried out very quickly. These subjective forced-tests can be good for something after all.

What I like just as much as the Thermoball is the stretch nylon taffeta. There just aren’t many stretchy puffy jackets out there, or at least not many that are styled like a puffy. The Stretch Thermoball gives the style and aesthetics of a puffy with the stretch of a technical alpine climbing piece. And I have to say, the stretch is remarkable. It isn’t just structural, in the sense that there are dedicated stretch panels; the fabric itself is incredibly inherently stretch, so you can feel stretch even when just tugging on the sleeve. Mind you, if you raise your arms above your head the hem will rise up with them. I am assuming people don’t plan on sending many V6’s in this puffy, so I think that’s OK.

Stretch this way

This jacket plays nicely as a lifestyle piece. It’s stylish and the Thermoball is undoubtedly a good performer. There are two aspects that make me raise my eyebrows: the first is the odd stitching of the pocket zipper tracks, which is almost like it’s mounted on a gusset. I find that the zipper heads snag a lot. The other aspect is debatable as a virtue or a vice, and that’s the fact that a cold wind can cut right through the hundreds of seams and intersections on the jacket. That means you can work harder in it without sweating out, but it makes it worse for being sedentary in cold weather. I tested a Medium and it fit my 5’11”, 185lb frame perfectly. I was comfortable in a midweight baselayer and this jacket down to the mid 40’s and got chilly in the high 30’s.

Stretch that way

The Good:

• Thermoball is great insulation – one of the best at mimicking down
• Stretch nylon taffeta is awesome! Really changes what a puffy can feel like
• Very nice, moderate fit
• Cuffs, hem closure and zipper track all do what they’re supposed to do without fuss or flare
• Above-average performance in wet weather

The Bad:

• Hand pocket zippers can snag easily
• Wind tends to cut through the seams