last winter everyone wanted to talk about Neoshell, this winter its Alpha.

as part of Polartecs aggressive campaign to update functional fabrics and the way they are used, more and more fabrics are being developed and more and more interesting ways are being found to use them.

polartec alpha insulation jacket various versions

variations for applications: theres more than one Alpha for more than one job

iceclimbingjapan in conjunction with Teton Mountain Project and Polartec has been working with Alpha for over a year, developing ways to make it do what high-demand users want. originally it was made for the demands of special forces (under another name) so demand was pretty high, but orienting it for the civilian market has broadened its application considerably.

like many, when we first got hold of Alpha we wondered where it sat next to other synthetic insulations like Primaloft, Coreloft and Thermoball, all of which had already been extensively developed. over a bbroad range of conditions and extended use, plus mixing it against different fabrics we worked up an idea of what can be done with it and from this developed garments that fulfil unique positions in the high-demand lexicon.

 heres what we have found

 doesn’t need baffling

Alpha is a 3d knit with its own  integrity, so unlike down, primaloft and thermoball it doesn’t need the extra weight and construction of baffles to hold it in place. this frees up all sorts of other properties of a garment

dries fast

make that ridiculously fast – up to 50% faster than other synthetic insulations. basically Alpha cant retain water, and tho other synthetics insulations can repel water this works against them by also trapping it, whereas Alpha wicks it away


the big seller. alpha has virtually zero vapor transmission barrier qualities which means even when faced in membrane or windproof fabrics it breathes better than insulation that repels vapor. by allowing vapor to reach the facing fabric without cooling the facing fabric works better for its intended properties.

alpha mesh inner facing breathable

the inner breathable mesh + an outer, non-membraned ‘shell’


being a knit Alpha has multi-directional ‘pull’ that means it can be face with stretch fabric. this means no more cold stretch panels and all that goes with them (ie cold spots from baffling and non-stretch seams). this means near-seamless ‘second skin’ insulation is suddenly much closer to reality.

alpha stretch jacket using powershield

try that with another insulation: with a mechanical stretch Powershield facing Alpha can form a body hugging ‘second skin’ layer that insulates super efficiently, moves with the body and repels wind and water – something that was only dreamt of not long ago.

heat transfer

Alpha allows heat to move thru a garment, which both vents the user and allows that heat to enter other things like sleeping bags and belay jackets, thus allowing those too to also dry. Alpha is an ideal sleeping fabric. where other synthetic insulations can get sweaty due to blocking heat transfer, Alpha reduces this.

polartec alpha insulation system

24hr fabric:  Alpha at its best when part of a clothing system that doesnt need removing. from high-output climbing to long hours in a sleeping bag, Alpha helps other fabrics dry by allowing heat to move thru layers.


next to the nearest fleece of the same insulation properties Alpha packs to about 2/3 the size. unlike some other insulations, long term compression doesn’t degrade function or cause cold spots. unlike other insulation with baffles or inherent hydro-affected properties, Alpha can be washed like any other fabric.

2nd fabric friendly

not requiring baffling, Alpha can be used with almost any other fabric, especially ones too light to hold the baffles that down etc needs. Alpha also doesn’t require down-proof fabrics, meaning it can be faced with meshes and open weave textiles that open up amazing potential for breathability.

construction friendly

being a knit, Alpha effectively already is a fabric, and so it combines seamlessly with other fabrics by being friendly to seam-locking and stretch-seaming where other insulations are not. this reduces bulk from internal excess and opens up options for paneling that makes for more ergonomic designs.

polartec alpha testing

integrated testing: Alpha demanded being tested along with other high-tier elements. here an early Polartec Alpha sample gets thrown in with other things to be tested over a wide spectrum of conditions

consider all this when you pick an Alpha garment off the rack. buying something in Alpha that is really just an old Primaloft design rehashed is a long way from seeing what the stuff really is all about. likewise, putting it against the same old uses and same old conditions also does little to expose its evolved functions.

over extensive testing we have used it from hot and humid conditions to waaaay below freezing, for multiple days without removing and in conjunction with every other textile and insulation we can find and have found it – when used to its potential – to be a new branch in high-demand garment. it doesn’t replace Primaloft or other water repellant insulations, theres much that they still do that Alpha doesn’t (ie Alpha plus Primaloft is a combination we are finding enormous potential and success with), but as a systemizible textile its remarkable.



(C)iceclimbingjapan 2013. use without permission is plagarism. write your own stuff.