Fleece VS Down VS Merino Wool – The Ultimate Midlayer Face-Off

Text by: Altitude Sports Editorial Team

Arc’teryx, Burton, Helly Hansen, Icebreaker, Mountain Hardwear, Norrona, Patagonia, Smartwool, The North Face. Fleece VS Down VS Merino Wool – The Ultimate Midlayer Face-Off

Gearing up for a weekend in the mountains? Packing efficiently and dressing wisely is crucial. Best to know how to layer for outdoor activities. An idea of the weather and the demands of the activities you’ll be doing will make choosing those layers simple.

While a base layer is the root of a good layering system, choosing the best midlayer is just as important. High-output activities that will make you sweat need moisture-wicking from all layers, not just the base. If your midlayer can’t breathe, there’s no point.

The three most common types of mid-layers found in an outdoor enthusiast’s wardrobe are down-insulated, wool, and fleece. We know them all, from puffy down jackets to fleece vests to sleek merino midlayers. Each has unique features and benefits – so how do you pick which one is right for your activity? 

down insulated mid layer

Down Insulated Midlayers


Cerium LT Hoody



Down Sweater Jacket


Mountain Hardwear

Super DS StretchDown 



Falketind Down 750


Down is natural insulation which retains heat better than most other organic materials. Used in all sorts of products like jackets and parkas, it offers outdoor enthusiasts supreme warmth. As an insulator, nothing beats it – but you don’t need down for every type of activity. Wet or damp conditions aren’t friendly to down. In dry climates is where a down-filled midlayer shines brightest – or warmest, in this case.


The pros are:

  • exceptionally lightweight
  • highly compressible
  • provides supreme warmth
  • retains shape & loft if dry
  • a long lifetime with proper care
  • breathable

The cons are:

  • loses insulating power when wet
  • requires special cleaning care
  • not hypoallergenic
  • higher average price

Ideal Use for Down Insulated Mid-Layers

Down midlayers are ideal for use in icy and dry conditions. They work well as stand-alone layers in dryer climates before temperatures plummet. Although down is breathable, it isn’t nearly as breathable as fleece. It’s a mid-layer more suited to lower output aerobic activities when some insulation is necessary.

Wearing a down midlayer isn’t ideal for anaerobic activities such as ski touring or running – it doesn’t evacuate moisture as quickly as other options. It is the perfect layer to put on while stopping for lunch when out mid-winter ski touring. The extra body heat from exercising will stay trapped inside. Down is ideal for strolling around town or taking the dog for a walk at your cozy cottage. It provides the warmth you need while your heart rate is relaxed during leisure activities.

Down mid-layers have also become fashionable pieces for life in cool and dry cities. They come in multiple styles that look just as great in an urban center as they do in an alpine forest.

Shop Women’s Down JacketsShop Men’s Down Jacket

fleece mid layers

Fleece Midlayers


Better Sweater Pullover



Hearth Full-Zip Fleece



Alpha Flash Jacket



Dallen Fleece Hoody


A fleece jacket is generally made from synthetic Polar Fleece, the most common type being Polartec polyester fleece. This soft-napped, insulating fabric is warm and soft next to the skin. These garments dry quickly and are durable enough for the most demanding outdoor pursuits.

Although fleece is not ideal for wet and windy conditions (excluding Windstopper Fleece in The North Face fleece jackets), they are exceptionally breathable and have excellent moisture managing properties. This makes them a near-perfect layering piece. They may be less compressible than a softshell or down midlayer but will provide warmth all day even when wet.


The pros are:

  • exceptionally breathable
  • quick-drying
  • excellent moisture management

The cons are:

  • lacks water resistance
  • lacks wind resistance

Ideal Use for Fleece Midlayers

Put a sherpa pullover midlayer on a cozy merino wool base layer and you have the perfect layering for a day on the trails. They’re especially optimal on hiking trips in all conditions because they are quick-drying, moisture-wicking and offer a quality amount of insulation. Because fleece garments and fleece-lined jackets are generally available in different weights, you can find the perfect one to trap your body heat while exploring the outdoors.

Shop Women’s FleeceShop Men’s Fleece

wool mid layers

Merino Midlayers


Satoro AR Zip Neck



Helix LS Zip



Intraknit Merino 250 



Quantum LS Zip Hood


While merino wool is usually thought of as a base layer, it also works well as a midlayer. Brands like Smartwool and Icebreaker specialize in merino and are making more midlayers than ever. Often these are blended with down or synthetic insulation for better heating.

Merino wool is known for its anti-odour properties, durability and minimal washing. A merino midlayer is a wise idea on an expedition with no chance to clean your gear. This versatility allows you to pack lighter because of how much use you can get out of a single merino garment.

Merino Wool

The pros are:

  • great anti-odour properties
  • superb temperature regulation
  • retains warmth when wet

The cons are:

  • not the best warmth-to-weight ratio
  • expensive

Ideal Use for Merino Wool Midlayers

Unlike fleece and down, merino wool midlayers are usually heavier and become even heavier when wet. For this reason, a merino wool midlayer is beneficial for short hiking trips, backpacking, or for traveling adventures. Due to their ability to regulate body temperatures in a variety of weather, these midlayers are great if versatility is a necessity.

If you are embarking on a more casual multi-day expedition with limited space, a merino wool midlayer is a smart choice because of its anti-odour properties. You won’t have to worry about smelling funky after one day of exercise, and you’ll stay sufficiently warm while needing only the one garment.

Shop Women’s Merino WoolShop Men’s Merino Wool

Midlayer Face-Off Conclusions

Everyone will have a midlayer preference depending on their own experiences, preference of feel and weight, and the activities they are doing. For those new to the process of layering for outdoor activities, the suggested breakdown above will help you dress appropriately. Over time you may find certain midlayers work better than others for your endeavors, or you may find that you prefer down, fleece, and merino wool midlayers for specific activities.

There is 1 thoughts on this article titled “Fleece VS Down VS Merino Wool – The Ultimate Midlayer Face-Off”.

  1. Great comparison!

    I’d like to point out though that anaerobic activity is an activity in which your body is working so hard that the oxygen you breathe isn’t enough to utilize your stored fat for energy. This results in your muscles using glucose and glycogen to produce ATP instead of oxygen + fat, thus anaerobic. This type of activity usually means short and really intense bouts at very high heart rates, i.e lots of sweating. Don’t mean to come across as a smart ass, just figured it was better to point it out than not…

Leave a Reply

Your email address will not be published. Required fields are marked *