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Insight · Wool Guide
Wool vs. Flannel vs. Fleece: What Actually Keeps You Warm
The short answer
Wool keeps you warmest in real weather. It stays warm when it gets damp, breathes when you work, and resists odor for days. Fleece is the warmest for its weight when the air is dry and still, but wind cuts straight through it. Cotton flannel is the most comfortable everyday shirt, and the first to lose its warmth once it gets wet.
Flannel is not a fiber. It is a brushed weave, and it can be made of cotton or wool. A wool flannel gives you the best of both. For cold days, wear them together: flannel against the body, fleece or wool over it, and a wind-blocking jacket on top.
Every fall someone asks us which is warmer: our flannels, our wool shirt jacs, or a fleece pullover. It is a fair question with a slightly tangled answer, because the three words do not describe the same kind of thing. Wool is a fiber. Fleece is a fabric, usually made of polyester. Flannel is a finish that can be applied to either cotton or wool.
So the honest comparison is wool, cotton flannel and fleece, with wool flannel sitting in between. Below is how each one performs on the things that matter outside: warmth, warmth when wet, breathability, wind, odor, weight, care and price. Then we cover when to reach for each, and how to wear all three on the same cold morning.
First, flannel is a weave, not a fiber
Flannel is a soft, napped fabric. The cloth is woven, then brushed so the surface fibers lift. That raised nap traps a thin layer of still air against your skin, which is why a flannel feels warmer than a plain cotton shirt of the same weight. It is also why flannel is not the same thing as plaid. Plaid is a pattern; flannel is a fabric. We wrote more about that in are flannel and plaid the same?
Most flannel shirts, including our Fairbanks and Waxhaw, are cotton. Traditional flannel was wool, and wool flannel is still made. Our Gunnison is a wool-blend flannel. When people say "flannel keeps me warm," they usually mean cotton flannel, and that is the version we compare below.
Wool vs. flannel vs. fleece: side by side
| Wool | Cotton flannel | Fleece (polyester) | |
|---|---|---|---|
| Warmth (dry) | High | Moderate | High for its weight |
| Warmth when wet | Best of the three. Holds much of its warmth when damp | Poor. Wet cotton pulls heat from the body and dries slowly | Fair. Keeps some warmth and dries fast |
| Breathability | High. Moves moisture vapor away from skin | High when dry | High, sometimes too airy |
| Odor resistance | High. Can be worn several days between washes | Moderate | Low. Synthetics tend to hold body odor |
| Wind | Good in a dense woven cloth | Fair in a tight weave | Poor. Wind passes through |
| Weight | Heaviest for the warmth | Midweight | Lightest for the warmth |
| Care | Wash less often, cold, no high heat | Easiest. Machine wash cold, tumble dry low | Machine wash cold, low heat or air dry. Can pill |
| Price at BJ | $139.95 to $184.95 | $89.95 | $99.95 to $144.95 |
Prices are for the pieces featured below: the Gunnison wool-blend flannel and our wool-blend shirt jacs, the Fairbanks and Waxhaw cotton flannels, and the Yosemite and Kodiak fleece.
Wool: the one that keeps working when things go wrong
Wool fibers are crimped, so they hold a great deal of still air, and still air is what insulates. Wool is also hygroscopic: it absorbs water vapor into the fiber itself. It can take on a good share of its own weight in moisture before it feels wet to the touch, and it keeps much of its warmth while it does. That is the reason men have worn wool on boats, in the field and on horseback for centuries.
The same quality makes wool comfortable across a range of temperatures. It moves sweat away from your skin while you split wood, and it does not turn clammy when you stop. It also resists odor far better than cotton or polyester, so a wool shirt jac can go several wearings between washes.
The trade-offs are weight, price and care. Wool is heavier than fleece for the same warmth, it costs more, and it does not like hot water or a hot dryer. Some people also find coarse wool scratchy against bare skin. A blend, or a layer between you and the wool, solves most of that. See is wool itchy? for the long version.
Cotton flannel: the everyday layer
Cotton flannel is the most comfortable of the three against the skin. It is soft from the first wear, it breathes, it washes easily, and it costs the least. A midweight cotton flannel is warm enough for most fall days and for working around the house all winter.
Its weakness is water. Cotton soaks up moisture, holds it, and dries slowly. Wet cotton pulls heat from your body, which is why outdoorsmen have long warned against it in cold, wet country. Rain, heavy sweat or a slip into a creek will turn a warm flannel into a cold one. For a day of hard work in the cold, wear the flannel as a comfortable shirt and let wool or a jacket do the heavy lifting. Our guide on how to wash flannel covers keeping one soft for years.
Fleece: light and fast, but weak in the wind
Fleece is a knit fabric, usually polyester, brushed into a thick, lofty pile. It gives a lot of warmth for very little weight. It dries quickly, and it still insulates somewhat when damp, which makes it a good mid layer for hiking and camp.
The weakness is wind. Fleece is so open that a breeze walks straight through it unless you wear a shell over it. It also holds odor more than wool does, it can pill with wear, and it will melt rather than smolder if you lean too close to the fire. Wear it under a jacket, not in place of one.
So which actually keeps you warmest?
It depends on the weather, and that is the point.
- Cold and dry, standing still: fleece and wool are close. Fleece wins on weight.
- Cold and damp, or working hard: wool wins. It stays warm when it takes on moisture and does not turn clammy when you stop moving.
- Windy: a dense woven wool beats fleece. Better still, put a wind-blocking layer over either.
- Mild, dry, everyday: cotton flannel is the most comfortable and the least fuss.
If you only buy one warm layer, make it wool. If you want the most comfortable shirt, make it cotton flannel. If you want a light, packable mid layer for dry days, make it fleece.
When to choose each
Choose wool for hunting, ranch work, fishing, long days outside, travel where you will rewear clothes, and any weather that might turn wet. A wool shirt jac works as a shirt on a cool morning and as a light jacket over a flannel as the temperature drops.
Choose cotton flannel for the everyday: the office on a Friday, chores on a Saturday, a fire in the evening. It is the shirt you will wear the most, and the easiest to care for.
Choose wool flannel when you want the feel and look of a flannel shirt with more of wool's warmth and moisture handling. It costs more than cotton, and it is worth it for cold mornings outside.
Choose fleece for dry cold when weight matters, as a mid layer under a shell, or as a soft pullover around camp and the house.
How to layer wool, flannel and fleece
You do not have to pick one. The warmest outfit on a cold day uses each for what it does best.
- Next to the skin: a tee or thermal, then a cotton flannel for comfort. On a wet or very active day, swap the cotton flannel for a wool flannel.
- The mid layer: a wool shirt jac or a fleece pullover. Wool if the day may turn damp or you will be working; fleece if it is dry and you want to stay light.
- The outer layer: something that stops wind. A wool jacket, a leather jacket or a down jacket. If you are weighing those, read wool vs. down: which is warmer?
A simple rule: the colder and wetter it gets, the more wool you want in the stack. And size your outer layers with the shirts underneath in mind. A shirt jac worn over a flannel usually wants the size you wear in a jacket, not the size you wear in a shirt. Our guide to what a shirt jac is goes into how to wear one.
Our flannel, wool and fleece picks
A word on our wool before the picks. Every wool piece we make, from the Gunnison flannel to the Yukon and Riverton shirt jacs, is a wool blend, and that is on purpose. A blend keeps most of wool's warmth and its natural odor resistance, which is what earns wool its column in the table above. The blend adds durability, helps the garment hold its shape, keeps the weight and the price down, and is often softer and less scratchy against the skin than wool alone. It is wool built to be worn hard.
Fairbanks Flannel Shirt | Lodge
Our top-selling flannel for a decade. Midweight 100% cotton, enzyme washed for a broken-in feel and pre-shrunk so it holds its size. Machine wash cold, tumble dry low. It comes in 13 plaids, from this classic red Lodge to the Pine Cove shown above.
$89.95
Shop the Fairbanks
Waxhaw Buffalo Plaid Flannel Shirt | Cane Creek
A midweight brushed cotton flannel in a bold buffalo check, with two open chest pockets. The louder cousin of the Fairbanks, in the same cotton family.
$89.95
Shop the Waxhaw
Gunnison Wool-Blend Solid Flannel Shirt | Dark Heather Charcoal
The answer to "flannel or wool?" is sometimes both. A wool-blend flannel with a streamlined fit, engraved wooden buttons and a shoulder-stitched patch. We call it a basecamp layer, and it earns the name.
$139.95
Shop the Gunnison
Yukon Wool Shirt Jac | Desert Valley Plaid
A mid-weight wool blend that is easy on the skin and tough on the weather. Wear it as a shirt over a tee, or as a jacket over a thermal or flannel. Prefer a cleaner, more modern cut? The Riverton Wool Shirt Jac ($174.95) is a mid-weight wool blend with hand-warmer side pockets and chest pockets.
$184.95
Shop the Yukon
Yosemite Waffle Fleece Pullover | Mesa Blue
A midweight waffle fleece built for layering, with a snap-up button collar you can open or close as the day warms, two front hand pockets and contrasting trim. It goes over a flannel by the fire as easily as it goes up a trail.
$99.95
Shop the Yosemite
Kodiak Fleece Pullover | Birchwood Green
A plush, insulating fleece pullover. Think less grizzly and more teddy. If you want a hood, the Kodiak Hoodie ($144.95) is 100% polyester fleece with a kangaroo pocket and elastic at the hood and hem.
$144.95
Shop the KodiakSee every flannel shirt or see every shirt jac.
Caring for all three. Cotton flannel is the easy one: cold wash, low dry. Fleece likes the same, with low heat or air drying. Wool wants less washing, cool water and no hot dryer. Always follow the care label on the garment. Our guides on how to wash a wool sweater, how to clean a wool jacket and how to store wool clothes cover the details.
Frequently asked questions
Is wool warmer than flannel?
Usually, yes. Wool holds more still air than cotton and keeps much of its warmth when it gets damp, while cotton flannel loses most of its warmth once wet. A wool flannel is warmer than a cotton flannel of similar weight.
Is fleece warmer than wool?
For its weight, fleece can be as warm or warmer in dry, still air. Wool is warmer in real conditions: when it is damp, windy, or you are sweating and then stopping. Wool also resists odor far better.
Is flannel cotton or wool?
Either. Flannel is a brushed weave, not a fiber. Most flannel shirts today are cotton, like our Fairbanks and Waxhaw. Wool and wool-blend flannels, like our Gunnison, are also made. Flannel is not the same thing as plaid, either.
What is the warmest layer for cold, wet weather?
Wool. It keeps much of its insulation when damp and does not feel clammy the way cotton does. Put a wind and water resistant jacket over it for the worst days.
Does fleece keep you warm when wet?
Somewhat. Polyester fleece holds little water and dries quickly, so it keeps some warmth when damp. It does not block wind, so wear a shell over it in wet, windy weather.
Why is cotton bad in the cold?
Cotton absorbs water and dries slowly. Wet cotton pulls heat away from your body. A cotton flannel is fine for dry days and around the house, but choose wool for wet or very active days outside.
Can you wear fleece over flannel?
Yes. It is a classic cold-weather combination. The flannel sits against your skin for comfort, and the fleece adds light insulation. Add a jacket on top when the wind picks up.
Which is easier to care for: wool, flannel or fleece?
Cotton flannel is the easiest: machine wash cold and tumble dry low. Fleece is close behind. Wool needs the most care: wash it less often, in cool water, and keep it out of a hot dryer. Always follow the garment's care label.
Is a wool shirt jac warmer than a fleece?
In wind and damp weather, a woven wool shirt jac is generally warmer because the dense cloth cuts wind and wool stays warm when damp. In dry, calm air a thick fleece can feel just as warm for less weight.
Are Buffalo Jackson wool shirt jacs 100% wool?
No. Our wool shirt jacs, like the Yukon and Riverton, and our Gunnison flannel are wool blends. A blend keeps most of wool's warmth and odor resistance, and adds durability, helps the garment hold its shape, and is often softer against the skin. It also keeps the weight and the price down.
Xan Hood founded Buffalo Jackson Trading Co. in 2009. He designs our flannels, wool and outerwear in Matthews, North Carolina.