Aerogel Insulation

We’ve recently noticed a new type of insulation showing up in outerwear. Many sites promote it as “NASA-inspired”, and they are not wrong. What we’re talking about here is aerogel, a very high tech and unique insulating material that found its original applications from NASA.

How does insulation work?

Outwear keeps you warm in three ways: conduction, radiation, and convection. Conduction occurs when objects are in contact (heat always moves from warm to cool), radiation is the transfer of heat as electromagnetic radiation (the body radiates mainly in the infrared region), and convection is the transfer of heat through fluid motion (air is a fluid, so wind causes convective heat loss).
Insulation helps slow conduction by trapping air, which has a low thermal conductivity.

Two common measurements of insulation value in outerwear include the insulation weight (in grams) and fill power. Weight is just what you’d expect — the weight of one square meter of insulation. Typically, warmer insulation is heavier. Fill power is the volume one ounce of insulation fills (higher fill is warmer because it traps more air).

What is aerogel?

Imagine a gel (gels are mostly liquid with a 3D solid network to hold them together) where the liquid is replaced with air — that’s aerogel (>98% air). Due to the size of the pores that contain the air, the thermal conductivity of an aerogel is far lower than insulation filled with air. Due to this extremely low thermal conductivity, aerogel insulation can retain its insulation ability even when compressed. This is due to the fact that while you can compress the air out of fibers embedded with aerogel (or in the case of an aerogel sheet, there isn’t much air to compress out), the aerogel itself is not compressed and still provides significant insulation.

The biggest issue with aerogel when it was first developed was that it is rigid and easily breaks into a powder. Since then various advances have given it some flexibility.


While it appears that other companies have made jackets from aerogel, OROS Apparel seems to have the oldest jacket still on the market. They developed what they call SolarCore, which is an aerogel in a polymer sheet. SolarCore is breathable and water-resistant, retains its insulation under compression (something many insulations can’t do), and is very thin and light. Their warmest jacket, the Orion Parka, claims to have been tested in stormy and below zero conditions — I’d say that’s a warm jacket!

PrimaLoft Cross Core and L.L.Bean

Just recently, L.L.Bean announced an outerwear exclusive with PrimaLoft for their new Cross Core technology. PrimaLoft has developed a way to fuse aerogel particles into their PrimaLoft Gold insulation fibers (here’s the patent if you’re curious) — this is called “PrimaLoft Gold Insulation with Cross Core”. Right now you can find this insulation in the L.L.Bean Packaway Jackets and the new line of Ultralight Sleeping Bags (35 °F semi-rectangular, 20 °F rectangular, 20 °F mummy, 0 °F mummy). The ability to retain insulation when compressed is a big plus for a sleeping bag, and not even the current standard, down, can claim this. Also, they seem to be at least half the weight of a comparable down bag (but they compress to a similar size).

Outdoor Research

Outdoor Research has also announced gloves utilizing a PrimaLoft aerogel technology (called “PrimaLoft Gold Aerogel”) for Fall 2018. We haven’t been able to find much information on these gloves, but they will most likely be unique in their thickness to warmth ratio. Also, from what we can find, it looks like this is a different technology in which the aerogel is encapsulated in a sheet that is not very breathable.

The Future?

We are excited to see how PrimaLoft builds on this technology as well as how our favorite outdoor brands utilize these two different types of aerogel insulation for the apparel industry.

Aerogel Insulation

Pistol Lake One-Bag Henley

You may have gathered by now that we are fans of the Pistol Lake Eudae fabric. The two pieces we’ve previously reviewed (the Minimalist Performance Tee and Raglan) are both made with the Lightweight Eudae. The One-Bag Henley is made with Midweight Eudae (76% polyester, 19% Tencel, and 5% spandex).


The Midweight Eudae is about twice as thick as the Lightweight. While not a heavy thermal shirt, this shirt is much more substantial than the Minimalist Performance line of shirts. I wouldn’t want to wear this shirt in the summer, but it would certainly be a top pick for any other season. As someone who gets hot during workouts, I could see this being a good shirt for hiking in the colder seasons, but would not want to wear it to the gym. Just like the other Eudae shirts, I can get quite a few wears before it needs to be washed. If I am getting sweaty, I can get about four wears, if it’s just normal wear, I can get about a week. This is better than I get with standard cotton or polyester, but not as good as merino.

Fit and Finish

As I’ve come to expect from Pistol Lake, this shirt fits me perfectly. It looks tailored with an athletic fit but is not too tight. The shirt length is also perfect, just a little longer than the usual. The raglan sleeves (meaning the sleeve extends in one piece to the collar, leaving just one diagonal seam under the arm) make for an extra comfortable shirt. These sleeves, along with the flatlock seams and odor resistance make this shirt live up to its “one-bag” name.

The only finish issue I’ve noticed is the bottom of the button placket was sewn slightly crooked — not something that is easily noticeable, but something I picked up on. I brought this to the attention of Pistol Lake, and as they are currently sewing a new batch, they will make sure to pay attention so no more go out like that. This, of course, is something that would be covered under their return policy.


The One-Bag Henley has taken a top spot in my wardrobe as a “nice casual” shirt — a step up from a long sleeve tee. It looks just like a nice cotton henley while performing better. While currently out of stock in almost all colors and sizes, this shirt should be back around the beginning of March.

Pistol Lake One-Bag Henley

Bluffworks Gramercy Pants

The Gramercy Pants are Bluffworks’ answer for a performance dress pant. The Gramercy line also includes a blazer, which we have reviewed. Made out of matching fabric, these pants share many of the same travel ready attributes. Being dress pants, these pair better with a jacket for a business event than something like an Outlier pant, which tend to look more casual.


The fabric is 100% polyester but doesn’t look it. From afar, it looks like a nice textured wool fabric. It’s only when you get close that you realize something is a little different about the fabric (there is just a slight sheen). There also was no “swishing” sound with these pants, something that gives away many performance pants.

The fabric is not advertised as having any stretch. However, I never felt uncomfortable traveling wearing these, even without them having stretch.

The wrinkle resistance of this fabric seems above average. I did not notice any wrinkles from wear that didn’t drop out overnight. However, when I received the pants, there were a couple wrinkles. Bluffworks customer service provided special washing instructions (wash hot rather than cold for normal care) to remove the wrinkles, and that took care of them.

As far as these pants looking good as a suit with the Blazer, I question that after seeing the pants (I have not seen them together, however).


I’ve worn these pants for a day of air travel as well as meetings and they were comfortable. Without much stretch, they weren’t as comfortable as my Outlier pants, but they were more comfortable than my traditional polyester dress pants.

I did have some issues with static on these pants, to the point where they were sticking to my calves and not dropping down after standing up. It is the toughest time of year for static (cold, dry, and windy), but I haven’t experienced this with my Outlier pants. Searching for solutions, I moistened my hands and ran them on the fabric where it was staticky — problem solved until I went back outside.

Extra Pockets

Some extra “travel” features these pants include are pocket zippers, a hidden pocket, and what Bluffworks calls a “security loop”.

Both front pockets have a zipper compartment (hidden about 1” in from the edge of the pocket). These are big enough for a passport, and I could see using them for that purpose. I found these zippers to be slightly annoying (they have a pretty large pull), and I made sure not to run my phone screen across them. If I were to make adjustments to the pants, I would have this zipper in only the left pocket and use a less obtrusive pull.

The right front pocket also has a “security loop”, which I guess you could clip your keys to, but I found it annoying, as my phone kept getting caught when trying to pocket it.

The left back pocket is completely closed by a zipper while the right back pocket is open.

Right below the belt line, slightly to the right of the right back pocket, there is a small unzipped pocket. I think the idea is to stow a phone, but I found it uncomfortable (but my iPhone X did fit).


The Bluffworks Gramercy Pants are worth checking out if you are looking for performance dress pants that look (mostly) like wool. I purchased these on sale for $125, but I think they are still a good value at $140. While not perfect, I have not been able to find better performance dress pants.

Bluffworks Gramercy Pants

Wool & Prince Blazer

This blazer was provided by Wool & Prince for review.

When shopping for a blazer, you will find wool is a common fabric. That probably doesn’t come as a surprise, but due to cost many have non-breathable linings or don’t use merino wool.

Enter the Wool & Prince Blazer. It is half-lined and made from merino wool. In fact, it is made with Pendleton merino fabric (one of the best wool mills in the world) and sewn right in the New York City Garment District.


While it is unusual for me to find an off the rack blazer that fits well, this blazer fits me very well. Your mileage will vary depending on your body shape, as the blazer only comes in slim sizes (S, M, L, & XL), rather than the more discrete standard blazer sizes based on your chest. I typically need a long jacket, but the sleeves on this jacket were just about the right length for me. Wool & Prince provides a size guide for some more information. For reference, I wear a L Regular in their button-downs and I have a XL Slim in the blazer.

In regards to how the blazer moves, since it is only half-lined, I never felt restricted — even when putting on or taking off my backpack. Of course, a wool blazer will never match the movement of a synthetic blazer but makes up for the lack of movement with a great drape.


Made with merino wool, this blazer looks just like a standard wool blazer. It drapes just as expected and the fabric has great texture. The patch pockets on the front definitely make it a blazer (so don’t try to match it with pants for a suit). While not as versatile as the classic navy blue, the charcoal grey of this blazer looks great.


The half-lining lends to the performance. It allows the merino to work its magic in regards to odor resistance and temperature control. I wore this blazer with a Wool & Prince Button-down and a merino undershirt in weather just above freezing and did not feel too cold walking between my hotel and car. If it were much colder or I was going to be spending time outside, a jacket would have been necessary. Typically, a blazer this warm would be too hot inside, however, this was not true with the Wool & Prince blazer. I was very comfortable in a day-long meeting as well as while traveling. I even wore the blazer to an Indian restaurant, and it did not have any hint of spicy smell when I left.

As far as wrinkle resistance, the blazer arrived folded up in a box with only one slight wrinkle. I was able to give the jacket a light steam and the wrinkle fell right out. The fabric can pick up small wrinkles in the elbows with wear, but they fall out easily overnight. While traveling, I was able to fold the blazer and put it in the overhead bin or on my lap without any issues. I imagine if it was jammed into a bag, it might come out with some wrinkles, but that could be easily fixed with a steamer (or a steamy hotel bathroom).

Small Details

This blazer has four pockets — one exterior breast pocket, two patch pockets, and one interior breast pocket. The patch pockets work well for holding my iPhone X, however, it sticks out of the exterior breast pocket (and the interior pocket comes sewn shut, but you can open it by cutting the thread).

The construction of the blazer is excellent. The half-lining is over the shoulder blades across the back, down the sleeves, and down the sides of the jacket and part of the front. The unstructured shoulders lay nicely. Also to note, the sleeve buttons are non-functional. This makes it easier for a tailor if you need to have the sleeve length adjusted.


This blazer is an amazing as an all-around piece for any wardrobe. It could be dressed down with jeans or dressed up with chinos or dress pants. The fabric looks, feels, and performs extremely well. I can’t imagine finding another wool blazer that I would prefer to wear over this one. Other than needing the extreme wrinkle resistance of synthetic, this blazer deserves top consideration.

The Wool & Prince blazer has become my new go-to for any occasion. I love how it helps regulate my temperature and resists odors. It makes a great travel companion or to dress up for a night out on the town.

Wool & Prince Blazer

Pistol Lake Minimalist Performance Raglan

This shirt was provided by Pistol Lake for the purpose of review.

The Minimalist Performance Raglan from Pistol Lake is the long sleeve (raglan) version of their core product, the Minimalist Performance Tee. Both are made out of their unique Lightweight Eudae fabric (76% polyester, 19% Tencel, and 5% spandex).

This quick review will focus on the fit of the shirt, as the fabric and performance is
covered in detail on our review of the tee.

Fit and Finish

This shirt is the best fitting long sleeve I’ve come across. It’s cut long enough and has an athletic (but not too slim) cut. The raglan sleeves get rid of the shoulder seams, this can make a difference if you’re carrying a backpack. The shirt also has a nice wide neck hole, which makes it even more comfortable than the tee. Even with the large opening, the neck never looks stretched out or puckered, like I’ve experienced with other shirts with this cut.

The only finish issue I found was a slight pucker where the tag is sewn in on the side seam. The Pistol Lake team is aware of this and will make a slight pattern adjustment for their next run to fix the pucker.


The Minimalist Performance Raglan has become my favorite long sleeve tee to throw on after work. If I wore long sleeves for exercise, this would also be my top choice.

Pistol Lake Minimalist Performance Raglan

Roundup #2

Interesting/New Products

Packing Lite wrote a review of the Wilderness Wear MerinoFusion Light 160 Long Sleeve Tee. The shirt is a very interesting blend of 50% merino, 50% Schoeller polypropylene. We haven’t seen anything like this before (and Schoeller fabric is what’s used in performance clothing like Outlier).


Pistol Lake is having a sale on some items through next Tuesday. Look for the products made with Eudae (while not included in the sale, the Minimalist Performance Tee we reviewed is made with their Lightweight Eudae).

CIVIC is offering 20% off through the end of the week (the discount will show in the cart).

A potentially interesting and inexpensive merino cardigan has shown up on Massdrop. However, note the low retail price — this means it is probably fairly rough wool.

Roundup #2

Workout Shirt Odor Resistance Comparison

If you’ve been around the performance clothing world, you should be well versed in the odor resistant properties of merino wool. While many tout the “magical” properties, we have not seen many head-to-head tests of merino vs. other fabrics for odor resistance.

The Test

I picked out three of my workout tees for this test — standard 100% polyester (Nike Dri-FIT), Olivers Convoy Tee (100% merino, our review), and Pistol Lake Minimalist Performance Tee (Lightweight Eudae, our review). I wore each shirt for my standard workouts (kettlebell or rowing), hanging to dry overnight, until each started to smell. The tests were repeated two times each.

100% Polyester

This shirt smelled after just one workout. The smell was bad enough that even if I were in the woods, I wouldn’t have wanted to give it a second wear. When dry, especially in winter, polyester gets terrible static cling. When wet or sweaty, polyester clings to your body in the worst way possible.


Eudae is a 76% polyester, 19% Tencel, and 5% spandex blend. I was able to get a respectable four workouts out of this shirt. If I were hiking I could have probably pushed it another day or two. Eudae is my favorite lightweight material — it is amazingly soft and comfortable, with just the right amount of stretch to get out of your way at the gym. It looks and drapes just like cotton, and does a great job wicking sweat without getting that damp clingy feeling.


100% merino turned out to be the champ. I was able to get eight-plus workouts out of this shirt. And really, when I decided to wash, it was because it was getting a little dirty looking. Merino is on par with Eudae on sweat wicking, however is not as good looking or comfortable. In the looks department, merino tends to have a slight shine and doesn’t quite drape like cotton (it almost has a “heavy” look). As for comfort, 100% merino has a decent amount of stretch for exercise, but it can sometimes be slightly scratchy when compared to other materials (this depends on the grade of merino).


If you want the best odor resistance, nothing beats 100% merino. If durability is important, you can find merino/nylon blends, but expect the odor resistance to decrease with increasing nylon content. For comfort and looks with respectable odor resistance, go with the Eudae. And the polyester — just forget it.

These performance tees can also become part of your regular wardrobe. With the extended wear you can get from them, it becomes easy to justify the higher prices (all while slimming down your wardrobe).

Workout Shirt Odor Resistance Comparison

Roundup #1

Interesting/New Products

We ran across Oros recently. They make outerwear with a NASA inspired aerogel (what they use for insulation in space suits) they call SolarCore. Looks like a neat new insulation technology at a compelling price (their parka is currently on sale for $250 with a regular price of $325).

Outlier dropped some new shirts including the S140 Pivot (merino, almost flannel button-up) with one pocket or a hidden pocket and the Freecotton Button-Up in white.

Wool & Prince launched their Heavy Crew Neck in their merino/nylon blend.

We noticed an interesting fabric, Polartec Delta, in a clearance Outdoor Research tee.

We saw an advertorial about the Lee Extreme Motion jeans. It’s unclear if the author actually tried the jeans, but definitely something that could be interesting at the price point.


Filson is having their winter sale. One interesting piece is the Alaskan Heavyweight Zip Top, made from merino wool.

Bluffworks is having a holiday sale with up to 20% off. They make some of our favorite synthetic business apparel, including the Gramercy Blazer.

QOR has an extra 20% off sale with coupon EXTRA20. We haven’t tried any of their stuff, but they do have both merino and technical options. They have a few pieces either insulated with Polartec Alpha or made of various Schoeller fabrics.


Abe of Outlier discussed why their Shelter from the Storm rain shell was made in China.

Roundup #1

Pistol Lake Minimalist Performance Tee

This shirt was provided by Pistol Lake for the purpose of review.

The Minimalist Performance Tee is Pistol Lake’s core product and is made out of their unique Lightweight Eudae fabric. The fabric is custom knit and the shirts are assembled in the US. Since developing this fabric, Pistol Lake has also developed a Midweight Eudae and an Eclon (their heaviest synthetic fabric). Their focus is on performance apparel that is at home on the road or in the woods as it is in the gym.


The Eudae fabric is 76% polyester, 19% Tencel, and 5% spandex. If you aren’t familiar with Tencel, it is a brand of lyocell fiber. This means it is derived from wood pulp. The Tencel brand is also know for its ecofriendly production process.

While the care instructions allow for machine drying, I’ve only machine washed and air dried the shirt. I have not seen any pilling or fading. This could be a nice benefit over merino for those who like to use a dryer.


This tee performs very well. From my experience, it is on par with merino in every category but odor resistance. While I can get 5+ workouts with merino, I can only get about 4 out of the Eudae. Keep in mind, however, I choose to wash my shirts when they start to get a little smell rather than let them get as bad as a standard polyester shirt is after one wear.

Fit and Finish

The fabric has great drape, looks like cotton, and doesn’t get staticky like many other synthetic fabrics. It is great to have a workout shirt that is very thin (but not sheer or see-thru) and breathable, yet still looks like a standard T-shirt. The fabric is completely matte and doesn’t have that “polyester sheen”, or even the slight sheen that some merino has.

I also find the fit to be perfectly athletic and slim while not tight or constricting of any movement. Unlike many of my other workout shirts, the length is perfect (I usually end up with shirts that feel a little short).


The Minimalist Performance Tee has taken the top spot in my workout wardrobe. Once the warm weather comes around, I expect it to become part of my non-workout rotation on the warmest days. If you are in the market for something that can hold its own against merino, Eudae is up to that challenge.

Ben’s Thoughts

I’ve been very impressed with the hand feel of this fabric. You’d not be alone in thinking that this was a standard cotton shirt, perhaps with some stretch in it. I really like it, it’s been a little too cold to wear it for me right now, but it’s going to be fantastic when the weather warms up. This is one of my favorite shirts yet, and it’s hard to believe it performs as well as it does.

Pistol Lake Minimalist Performance Tee