What’s the best winter insulation?


f the phrase was “when in Wisconsin…” it would most certainly suggest eating brats and cheese curds, drinking beer, watching our many athletic teams - and knowing your stuff when it comes to surviving our winters. Depending on the conditions, what you wear can make or break your experience in our unforgiving climate. But what offers the best insulation? Knowing the differences between down, synthetic and wool – and how they each perform - can help you make that important decision before you venture out.

Before we get to the nitty-gritty of differentiating these materials from each other, there are a few key items to mention.

Layering is key. In especially chilly temperatures, the most effective approach to insulation is starting with a wool base layer, incorporating a down or synthetic mid-layer (vests are a great solution if you’re looking for added warmth, not bulk) and finishing with a down or synthetic outer layer, depending on what you’re doing and what the weather’s going to be (cue the glorious winter wind and sleet!).

- In terms of down and synthetic, take a look at the piece you’re considering to see if it employs sewn-through or baffledconstruction. If it’s windy out, you’ll want to opt for a baffled piece, which stores the insulation inside of tiny little boxes throughout the garment, offsetting the seams. Sewn-through is typically better for breathability, but also creates cold spots if conditions are particularly chilly. Some sewn-through pieces are reinforced with a backing to enhance insulation. We find that Mountain Equipment and Rab particularly excel at baffling, even around the zipper.


The key differences between down, synthetic and wool are: moisture resistance, insulation, compression (and ability to regain loft after compression).


What is it? Where does it come from?

Down is widely considered to be the warmest (for weight) and most efficient insulation available. Down is sourced from the layer of feathers – or its undercoating - closest to a duck or goose’s body.

As a company who’s intrinsically concerned with sustainability and the wellbeing of animals, how animal- and earth-friendly is down?

Yellow Wood prioritizes carrying products only from brands who treat animals and our environment with respect. Our brands include Canada Goose, Fjallraven, Arcteryx, Rab, Mountain Equipment, Lole and Kuhl and Nau.

What is “fill power” and how do I determine what’s enough?

Fill does not mean weight nor density. The lighter and more fluffy the down, the greater the fill and the loft. Fill power (FP) refers to the fluffiness of the down. Generally speaking, quality jackets feature fill power ranging from 550 – 1000 (yes, 1000 can be done!) Rab developed the Zero-G, the first 1000FP to hit the market.

How does fill power relate to compressibility?

 The higher the fill power (and the loftiest), the more compressible the down. 

How is fill power measured?

One ounce of down is placed into a cylindrical tube. A light weight is applied to the top of the down for one minute and subsequently measured by volume in cubic inches.

What is traceable down?

Traceable down is just that – traceable. When you purchase a down garment from brands such as Mountain Equipment and Rab, you can actually trace the exact source of the down that was used to make it. Doing so helps maintain the highest standard of ethics and treatment of animals.


What is it?

Synthetic is constructed from polyester fibers arranged into filaments to mimic the qualities of authentic down.

What edge does synthetic have over down?

Synthetic offers superior moisture control and maintains a great deal of warmth even when wet. Further, synthetic tends to be a more affordable option when compared to down and is hypoallergenic.

Is it sustainable?

Some versions of synthetic utilize recycled materials, but it often doesn’t have the longevity of down. Using synthetic also removes the need for animals – effectively removing the concern of enforcing animal-friendly practices. Some of the brands we carry who use sustainably- sourced synthetic include Mountain Equipment, Arcteryx and Fjallraven.


We’d be remiss not to bring wool into this conversation. Recent advances in wool technology have really made this fabric a viable, reliable, environmentally-friendly option for insulation. (Wait, I missed the memo. Wool isn’t itchy anymore?!)

What is it? Where does it come from?

Wool is sourced from sheep. Where those lambs are geographically varies by brand. For Duckworth, its Dillon, Montana. Most wool, however, especially merino wool, is sourced from Australia.

Is it earth- and animal-friendly?

The wool industry was at one point known for an inhumane practice called mulesing. The founder of Icebreaker, Jeremy Moon, states, “there’s no point in having quality if you don’t care for the animals and the land in a sustainable way.” All of the brands that we carry at Yellow Wood have that same mentality. For ethical, eco-friendly products, be sure that the products you’re purchasing use ‘non-mulesing’ wool. 

Our favorite wool brands include Duckworth, Icebreaker, Kari Traa, Arcteryx and Woolrich. For socks, we love Sockwell, Fits and Point6.

Winter is in full effect! Get in here so you can get out there – comfortably! The team at Yellow Wood in Whitefish Bay are Wisconsin winters and we’re happy to help you find a solution that works for your lifestyle! 

Liz MartinYellow Wood