Nunatak Jackets with Synthetic Insulation

Nunatak Jackets with Synthetic Insulation

Apex by Climashield is a continuous fiber synthetic insulator replacing down in some of our jackets. It performs better in moist conditions and is not as affected by sweat compared to the extreme hygroscopic nature of down. Apex is durable, with a long usable life and good recovery from repeated compression cycles.

We have two lines of custom Apex insulated jackets (aka puffies): the original Skaha and the superlight JMT Jacket. While seemingly overlapping in qualities, they are two rather different products. More about this in a bit.

Definition of the levels of Apex insulation we offer.

2.2 oz/sq.yd. JMT Jacket only. Thin, light, compact. Strictly for weight-weenies.

2.5 oz/sq.yd. While only a small step up from 2.2, this level feels more capable. Our favorite. Year round use with smart layering.

3.6 oz/sq.yd. Shoulder season high mountain applications.

5.0 oz/sq.yd. The upper limit of what can be sewn into our designs. You will know if you need to go to this extent of warmth.

As custom products we can build our jackets precisely how you want them. Some customers mix it up with warm torsos and lighter arms, etc.

Moisture infiltration.

While Apex responds well to damp conditions, the claim 'warm when wet', often seen describing synthetic products vs. down, is misleading. Our Apex jackets are not warm when wet. They do, however, have numerous advantages over wet down jackets:

Given similar scenarios Apex will not get as wet. 

Drying Apex jackets will get rid of their wetness quicker.

They will rebound to full efficiency without damage to the fill.

So what does that tell us about Apex? Don't get your stuff wet, but if you do screw up it won't be as bad as it could be with down.

Durability of Apex.

Apex is known, perhaps anecdotally, as very durable, able to withstand endless compression cycles and good for repeated washings. Even without exhaustive tests to back this statement, it is nonetheless important that we find the word ‘durable’ connected to a synthetic based insulation. Why? Well, synthetics historically have been dismal in that realm, some barely surviving the initial visit to the laundromat with any loft left. Apex is one of the first to break with this unfortunate image. Our experience, although relatively short, backs these claims.

Do you still need to baby it? Yes, off course. Any backcountry insulation product depends on delicate fibers trapping air. 'Delicate fibers' does not respond well to abuse, no matter the make up. Don't use a compression stuff sack with mechanical advantage. Store fluffed up. Wash only when stinky, not merely dirty. Other than that - go for it!

Shell material.

Both the JMT and Skaha Apex are offered with ultralight 10d shells that are super thin, very breathable, comfortable and smooth. 

You can also have them built with a super ultralight 7d material with remarkable water proofing qualities. This is what we call the Robic. It’s a good deal more expensive but provides, at no significant weight increase, an effective barrier against the weather. Breathability is still at an acceptable level, but low enough to also experience a boost in the temperature rating, again with no weight penalty. Altogether the winning material here, we feel.

Brief rundown of the principal differences between the JMT Jacket and Skaha Apex.

The JMT is okay warm. It's an insulated windbreaker cut so trim you can't really layer up under it. In the mountains in summer it’s perfectly fine, especially with the effects of climate change. It looks smart and makes you fast, while having a magic ability to adapt to a broad range of conditions - to the point where you can actually hike while wearing it, even with a pack on.

The more versatile Skaha is cut roomy to go on top of every other piece of clothing in your pack. Built with the warmest of the three levels of insulation lofts available it can be classified as an ‘almost winter parka’; with the lightest it’s a very efficient ‘go anywhere’ piece of equipment.

The JMT can be configured using a minimal set of options.

The Skaha is presented with a vast array of custom features.

The JMT is stupid light.

The Skaha is ultralight.

Who would be using what jacket where?

JMT, where: Modern UL backpacking. Endurance FKT races. Thru hikes. Year round snow free day hikes.

JMT, who: #hikertrash (as popularized by Hummingbird’s book)!

Skaha, where: All season backpacking. Alpine climbing. Snow sport day trips.

Skaha, who: Adherents of the One Puffy Quiver.

How are synthetic insulated puffies performing in the backcountry?

In short: very good. 

It is our absolute belief that these jackets will outperform their lightly insulated down competitors.

While synthetics are not completely immune to moisture, the much greater tolerance they offer is a massive advantage.

The lack of closely spaced quilting (ubiquitous on lightweight mainstream down and synthetic puffies) takes better advantage of the inherent insulation value of the Apex. There’s not a grid of sewn-through stitch lines up and down the jacket to bridge cold and wind directly inside. The stitch lines you do find are spaced several inches apart and is only on the inside. 

The Apex insulation makes up in excess of 50% of the total weight. While this doesn’t necessary make the jackets warmer, it helps keeping your pack weight low - an asset also filed under ‘backcountry performance’.

Finally, but not least: with a bit more resistance to compression over down, Apex jackets make superior pillows.

For optimum success balancing weight and performance, make sure to choose the correct level of insulation to be built into your puffy. 

Limits to custom requests.

Nunatak does custom work. This means that if you do not find an option you need on the website you can talk to us about fixing this. For example, we stock numerous fabrics more durable (and heavier) than the ones seen on the order page. All these can be used on both the JMT and Skaha.

Here are the most notable design exceptions:

We do not offer the JMT Jacket with exterior pockets.

3.6 oz/yd Apex is the upper limit for the JMT.

The Skaha cannot be spec'ed with a full front zipper.


    • Avatar
      Steve Holland
      Feb 9, 2018

      Hi do you offer hyperD fabric in colors other than crimson or royal blue? Would you be able to build the JMT with hyperD? If so would that cost more than the 10D or robic .74? Thanks! Steve

      • Avatar
        Apr 15, 2018

        Steve, so sorry I overlooked your question! Yes is the answer. No extra cost - same as standard 10d.