Lofty Fleece Layer

there aint no such thing as a free lunch…

as the graph from westcomb clearly shows … by have an "active" synthetic layer you sacrifice the "warmth" of the garment

remember that if its more breathable, ie more air moving through it tends to be less warm … after all the purpose of down and high clo synthetics is to TRAP the air …

;)

"If 2.5 oz Apex is about equal in warmth to a 400 wt fleece…"

This may be true in some (emph. "some") lab tests, but it isn't accurate anywhere else. Static clo values don't tell as much as most think.

Hi Jeff,

If you're talking about "mjrep", i had bought some of their Polartec Powerdry High Efficiency Baselayer fabric.

Just be careful to ask them ahead of time, what exactly the fabric looks like, the stuff i received did not have any fleecy parts on it and it was a bit hard to tell that from the photo. Their current, Polartec Powerdry High Efficiency Baselayer 2.3 yards Black fabric from the photos look like it does have fleece, but i would ask to make sure before actually purchasing.

One consideration to keep in mind, with using super breathable fabric like the above, it might be possible from some of the Apex to migrate through the fibers of said lining over time. Wouldn't happen with the breathable ripstop nylon, but could possibly happen with the PPHE stuff. In turn, that would decrease longevity, and possibly act as a skin irritant.

Good points, Justin. May be better to just use a breathable ripstop, then.

Eric, there isn't enough information in that graph. We don't know if the difference in CLO values is because of the lining differences, or because of thickness or differences in the insulation itself. Unless wind or fast movement is involved, linings/shells aren't going to be a big factor in warmth of lofty insulation.

It's hard to say, because Polartec is being kind of secretive about it, but it seems like the Alpha stuff is a kind of slightly revised and lighter Polartec Thermal Pro type insulation, with semi-breathable linings encasing it (polartec has a long history of slightly revising a past iteration of their technology, and then calling it a whole new and "much better" thing). If that the case, it's not going to be as warm per weight as Apex, Primaloft, etc.

In any case, it's kind of a moot point, because i still plan to have a windjacket with me, so if i do get cold with it, just put that on.

That's the point of said system, is the inherent flexibility and adaptability of it. For me, it's not even about weight savings, though certainly a 2.5 oz Apex vest made with breathable 1.1 oz nylon and only one layer of fabric on the back, is going to be pretty darn light. I'm estimating around 3.5 to 4.5 oz for it. We soon shall see.

If you want a really breathable and light outer shell to act basically as a scrim, pick up some 4.5mme silk! Not sure if the insulation would poke through it though, but should be plenty breathable until you add a windshirt.

Also I'm getting an r2 today and for the weight that is what I think of as "lofty fleece." All this 100wt fleece chatter is off topic imo. I will say this, I feel colder wearing a slim fitting fleece than I do wearing a regular baselayer. While my torso may in fact be warmer, the fleece conducts the effects of wind so well that I get localized cold spots that chill me. Remember our bodies are not static, there is an active nervous system that responds to triggers as much as it does to absolutes. This is why you shiver when you place an icy can of soda on your neck in the middle of summer. These effects can cause your body to react in negative ways to cold weather stimuli (ie false sense of warmth or false sense of cold).

In these situation I find moisture mitigation tends to be teh best way to damper the system. Chenault has been alluding to these dynamics in his recent cold weather articles over the last year or two (and in this thread).

Remember there are two characteristics in play here, global behavior and local behavior (take a course on pdes, dynamic systems or chaos if you really want to understand warmth, since it's all basically complex thermodynamics). In layman's terms that's basically the need to balance total warmth (global and controls hypothermia) and rate of warmth change (local, also your body's "perception" of warmth). As Jerry said, take clothes off ASAP to control both as conditions dictate, but if climbing like Eric explains prevents proper thermoregulation we then have new constraints. In that case (and in general) I prefer to not "feel" cold over actually being cold while I'm moving. On the move I'm actively generating heat, plenty of it usually, so I don't worry about hypothermia. I have a big puffy for that. What I do care about is feeling chilled and shivering when my core temp is high enough, because then I'm wasting energy. This comes from moisture control far more than any actual clo value. So if you can't cool yourself off enough and will sweat no matter what (eskimos are shaking their heads) then it becomes more important to move that sweat off your skin…not necessarily to completely remove it, just to remove it from skin contact. This is why grid fleeces (and to an extent wool) feel warmer.

TL;DR version. Wear your dang fleece and see what you like. As long as you've got a big synth/down puffy that you keep dry you'll live to try a new system!

Hi Jeff, if making a vest like the one I'm talking about, you could still use the PPHE fabric for the part going over your back. It would be really preferable to have that fabric on the back then the rip stop nylon.

I've considered silk and though I really like silk, the moisture management properties and durability aren't ideal for this application. I would more consider it for the inner of a Apex quilt though.

BTW, nice, holistic post on fleece and warmth Dustin

The charts on fleece are good for comparison, but the way I use fleece is as an intermediate layer, with a light base layer and capped with my windshirt or rain shell for maximum effect.

I wear fleece by itself for a quick warm up on a cool morning or windless rest stop, but most of the time it is part of a 3-in-system with a shell. That slows the air transfer and turns all those thin grids into fat pockets of warm air that can still breathe.

I'm not looking for cold weather use with fleece so much, but more for cool/wet weather stuff. The "long hair" fleeces have more warmth, but for UL hiking I think they tip the teeter-totter for weight and bulk both and lofted fiber fillers like Primaloft and down become the preference.

IMO, a hiking wardrobe locker sould have a couple weights of base layers, some fleecy mid layers, lofted fill jacket and vest, and wind and rain shells. These can all be chosen for the expected conditions and used interchangeably.

My own locker looks like the list below today and covers from hot summer to mid-20's F, what I would call "4-season light" in the Pacific NW Cascades and Olympics. The fleece covers from mid-40's to 60F and can supplement the Primaloft layers and my sleep system for colder weather. My philosophy is to dial in base layers and pants for strenuous uphill walking with a backpack in the daytime temperatures expected, always assuming the use of a windshirt as needed. Supplemental insulation is chosen for the expected lows for rest stops, camp or an unexpected night out. Rain gear, gloves and beanie are always carried.

My full wardrobe list:

Silk weight polyester short and long sleeve shirts

Capilene 2 and 3 and light Power Dry long sleeve shirts

R1 vest and cardigan

Primaloft vest and hooded jacket

Windshirt

2.5 layer rain jacket

Poncho

For bottoms:

Silk weight long johns

Medium and heavy weight Power Dry long johns

Supplex nylon zip off pants and shorts

Light and medium weight soft shell pants

2.5 layer rain pants

Accessories:

Shelled water restant gloves

Fleece liner gloves and mitten shells

Hard faced synthetic gloves

Light fleece beanie

Light merino beanie

Fleece balaclava

Rain hat

Sun hat

Insect repellent bandana

Foot gear:

Merino wool socks

Keen Newport sandals

Low top non-waterproof shoes

Waterproof mid boots

Low and high top gaiters

The best clothing kit is a versatile system with all of the parts working together and interchangeably. Several layers are always more versatile than a thick single layer. Attention should be paid to moisture management, ventilation and breathability. Weight is best managed by the versatlity and performance of the system, aiming at realistic coverage for the conditions expected. Understanding your needs and how layering systems work will insure that you have enough clothing that works. In a perfect UL world, you should be wearing everything when meeting the coldest temperatures.

The importance of accessories should not be underestimated. For example, the perception of cold from cold hands and ears have a lot of psychological effect on your overall comfort.

My $0.02 :)

Eric wrote: "there aint no such thing as a free lunch…

as the graph from westcomb clearly shows … by have an "active" synthetic layer you sacrifice the "warmth" of the garment

remember that if its more breathable, ie more air moving through it tends to be less warm … after all the purpose of down and high clo synthetics is to TRAP the air …"

'Tis all compromise. Whenever evaluating an insulation system, activity level, ambient temperature and humidity need to be considered. In that I see fleece as a cool/wet weather item as opposed to sub freezing conditions, I think the moisture-shedding properties need to be considered. If the warm air you are holding in is damp, you generally took a step forward and two back. That's where I value a fleece vs the thin 40-60g synthetic or down jackets with two much less breathable shells.

Take the fleece and trap the air with a nice breathable shell and you have something you can wear in those sneaky hypothermia prone conditions like 45F and 90% humidity. If I'm wearing fleece at 20F, it will be under a fat layer of Primaloft and the most activity I will be having is dancing on one foot with a cup of hot jo :)

Dale, you bring up a good point and thats why we now have the hybrid jackets so favored by climbers. The synth insulates the lower perspiration areas of the core while the fleece sides and underarms allow you to dump the more moisture saturated air your body produces! Granted these are only suitable in very cold conditions or with frequent hurry up and stop trips with short duration times.

Studies of insulating materials have shown that insulating fibers with more surface area PER WEIGHT have more "Boundry Layer" air. That layer is the one to two molecule layer of air that adheres to insulaton in an electrostatic fashion. Boundry layer air tends to remain in place, even with convection moving adjoining air.

That is why down, with its millions of tiny "barbs" on the plumules, is so warm. LOTS of boundry air.

And that may be why Primaloft & TNF's Thermal Ball insulation is pretty good. Thousands of tiny fibers per cubic inch. (But… will it retain its loft over repeated stuffings and wear? "Ah! There's the rub.")

as with many, I've got my primary layering system dialed-in and built around a lightweight synthetic base layer, fleece hoodie (power stretch) and wind shirt (epic). depending on anticipated temperatures/conditions my stationary primaloft layer would be (i) 2 oz (wt hooded insulight), (ii) 4 oz (wt hooded sweater) or (iii) 6 oz ( wt belay jacket). I also have a ff volant that I find myself reaching fro with more frequency. While I’ve historically harbored a somewhat irrational fear of somehow sufficiently soaking my down jacket to the point that the insulation was severely compromised, I’ve gotten my brain around the concept that if it’s cold enough to wear 11oz of down, water exposure will be pretty well limited. I’m trying to put some general guidelines together for myself as to where the break-point would be for using/not using fleece as an insulation component. The plan is to figure out what temperature/conditions under which I ditch the hoodie and wind shirt and wear the insulight over my base layer. While the insulight alone gives the appearance of less flexibility with having the shell integrated with the insulation, the jacket is both warmer and less weight than the fleece and wind shirt combination it would replace. The insulight will fit under all three of my heavier insulating layers.

I think a lot of UL clothing issues revolve around our perception of the role of the garment compared to what we use as street clothing, like categorizing a windshirt as a shirt or a jacket. It dawned on me that I use fleece as I would a sweater. The only difference in my expectations are that fleece is better in wet conditions and is generally lighter for the loft provided. I think that may help to understand the best use in layering.

that's a great analogy and makes perfect sense. what we are referring to as a "fleece" is the technological evolution of the sweater. it wasn't too long ago that my prized oiled wool sweater was my cold weather/sailing go-to garment, alone as part of a layering system under a woolrich 60/40 with the plaid wool lining or line7 foulies. and who in the 80's and before, didn't have a ragg wool sweater as part of their outdoor kit. they were warm, brethable and provide some water resistance.

I used to wear a ragg wool sweater for cross country. They were durable and warm and would stretch to your knees if wet.

The sweater thing smacked me when looking at my r1 hoodless jacket, which is just a zip cardigan. Duh.

The Brits have added wool vests to their tweed sport coats for ages, dealing with cool damp climates and no central heating. My R1 pullover is really no different.

Patagonia even markets the "better sweater" which is good town wear. It would work on the trail, but is a litlle heavy and bulky.

This thread prompted me to get a fleece layer, which has been missing from my backpacking closet. I just ordered a Paty Cap4 EW hoody and bottoms. Looking forward to trying them out, perhaps in Michigan.

"I just ordered a Paty Cap4 EW hoody and bottoms."

You're going to love this outfit. The hoody is a great layer, either next to skin or over a lightweight 3 season base layer. I used it last year next to skin on strenuous day hikes down to the high 20's-low 30's, with a Rab Boreas over it until I warmed up and for windy conditions. This year I added my Arcteryx Motus 3 season base layer underneath as my cold tolerance diminishes with the addition of another year. It is the best cold weather active layer I have ever come across. You've got a little more insulation than I, so you might be able to get away with it next to skin. Either way, I think you're going to be very pleased with your purchase.

I dawned on me that Capilene 4 is the same or at least very similar to Power Stretch. It's great as a summer mid layer and as a "super base layer" under rain gear and stacked up with puffy layers. It doubles as the best hiking pajamas around, although I would find it hard to justify a whole set of the stuff for dedicated sleep wear , which would be 20oz or more. It sure extends the range of a sleep system in a hurry and you get all the water-hating and breathability qualities.

It is spendy stuff. EMS has turns out some nice Power Stretch hoodies — keep an eye out for sales.

"I dawned on me that Capilene 4 is the same or at least very similar to Power Stretch. "

The Patagonia web site says the current Capilene 4 is 3.8 oz Polartec Power Dry High Efficiency

Yeah, the current Cap 4 stuff is pretty light. Pants are 5 oz and the Top is 8oz or so, you're under a lb for the pair, likely even in the largest sizes. Still I think the stuff is too warm for pants in anything but the coldest situation.

Now out here in the desert, I may consider the pants and hoody as my summer sleeping bag with a bivy ;). Actually that idea demands testing in the future. For now I'm just waiting for UPS to drop off my new cap 4 hoody (I got my R2 yesterday and am loving it).

Patagonia should sell swatch sample sets. It's hard to keep them all straight!

Doug, it's very nice stuff. I've been rocking a purple women's XL version of Pat. Cap. 4 hoody. Unfortunately, it's not the latest one which uses Polygiene (silver salt ions), but the version that used Gladiodor, which will eventually wear out. Polygiene treatments are supposed to be more or less permanent for the life of the garment.

Max

Picked up one of these for $55 to my door. I have to agree with you completely on all your points. Loving this thing. Bought it with the intent to wear it in the house through these cold months, but I'm just leaving it on all the time. It's as simple as could be, very well made and very versatile! I see getting a lot of use out of this backpacking.

…and the best part, my size small comes in at 6.9oz on my scale.

One happy camper with that purchase.

KJ