The Introduction page will define the principles involved in layering and list over 60 products from 18 manufacturers which are described in this dissertation. Each product on the list is hyperlinked to the product listing on the Product Descriptions page.

Use the Layering Index links below to jump to a section.

This dissertation may offer more than you want to know. I recommend that you read this Introduction,
followed by the Summary. From there you can use the Index to branch out into an area of interest to you.


Layering Index



Base Layers: Synthetic and Merino

Field Shirts, Pants, and Outerwear

Legacy Synthetics

Summary and Recommendations

Product Descriptions

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Bison in Snow Gibbon River 5715

Rangers paddle a canoe on the Gibbon River past a group of Bison foraging in a
snow-covered meadow at Yellowstone National Park at the end of winter in late April.

Principles of Layering: an Overview

Obviously, when dressing for colder weather you want to make sure that you are warm enough based upon the levels of activity anticipated, but the bigger problem is becoming too warm and sweating. When you stop generating body heat, you can easily become chilled if wet clothing is next to your skin. It is important to select materials which effectively transport sweat away from your body by capillary action (wicking) where it can evaporate without cooling the skin. You should select your kit based on knowledge of the weather conditions in the area you will visit, with flexibility as a primary consideration. The object of dressing in multiple layers is to give yourself the ability to remove layers as you get warmer, and easily put them back on when you cool down. Several lighter layers are better than fewer heavy layers, and as many people know, you can lose a lot of body heat through the head and neck, so it is a good idea to cover those areas and to select garments which allow you to zip down the various layers to vent excess heat, or zip them up to hold heat in. Some materials are more efficient than others, and one commonly used material (cotton) can be dangerous. This discussion will concentrate on the most commonly used material in outdoor clothing (polyester) and a material which has been gaining a lot of converts in the outdoor community (Merino wool), and will address the use of these materials both separately and in combination.

Layer categories are separated into base layers (next to the skin), mid layers (added atop the base layers to add warmth without adding bulk), insulating layers of fleece, wool or down worn in cold conditions under the shell, and the outerwear (hard shell or soft shell, either water resistant or waterproof). These layers are available in several weights, and often midweight base layers are used as mid layers, and heavy base layers can be used as insulating layers as an alternative to a sweater, vest or insulating jacket.

This discussion will be approached differently than the other pages in the Guides section. Rather than showing pictures of each product along with the information, I will instead provide links to the clothing manufacturer website, with the exception of current synthetic and Merino base layers, which will have comparative composites of interior and exterior surfaces, and will include a link to the product page on the manufacturer website. This dissertation will describe over 60 products from 18 manufacturers.


Elk in a Snowstorm 5719

A female elk peers at the photographer through a late April snowstorm on the Gibbon River in Yellowstone.

The overall goal was to explore the characteristics of current materials, both natural and synthetic, with the purpose of creating multiple options for various conditions. Each of the critical inner zones were experimented with: the core layer (one or more light layers next to the skin, required to regulate body temperature and begin the process of moving moisture away from the skin); the mid-layer (one or more layers that provide some insulation, continue moving moisture away from core layers, and preferably can act as a light top layer as temperature or activity levels increase); and the insulating layer (one or more layers which provide greater insulation, effectively move moisture, and preferably can act as a midweight top layer as temperature or activity levels increase).

I worked with my existing Marmot softshell and Mountain Hardwear hardshell jacket, adding a lightweight two-layer light shell consisting of a windshirt (or midweight base layer) and a Patagonia pullover hardshell, which most often is used in place of the Marmot due to greater flexibility of use, greater resistance to a heavy storm, and the ability to pack smaller and lighter.

The ultimate goal was to have the ability to create synergistic components which could be used to construct the most flexible kits for the conditions likely to be encountered. Having the option to select components which offer the most benefits in the specific sub-conditions, yet which operate synergistically with other component sets, allows you to cover all anticipated situations while maintaining the least weight and the smallest packing volume. The primary component groups (core, mid-layer, insulation layer, light shell, heavy shell) may not all be necessary, and sometimes it makes sense to split a primary component group into two complementary items. When components work well with those in the groups around them, you can more easily eliminate a component on one side or the other in the field to adjust to changing conditions. I often find myself splitting either the mid-layer or the insulation layer into two components, especially in conditions where I will not need a heavy shell.

I select very different types of arrays for very cold to mild conditions; cold to warm; or chilly to hot. I generally use Merino for core and mid-layer, mixed synthetic and Merino for insulation layers, and synthetic top layers.

Base Layer Materials

Regarding the use of cotton, it is best used in warm or hot dry environments where the tendency of cotton to retain moisture and minimize water loss from your body while keeping you cool are desirable characteristics. I have seen folks using Arborwear jeans and a Faonnable 1/4 zip cotton top reasonably often (maybe I just notice them because I have them too), but if they get wet they take forever to dry and in the mountains or other cold environments, this can lead to hypothermia. It is best to keep products like this for use in dry areas or in the city.

Nearly everyone has a few sports synthetics in their drawer. Properly designed synthetics wick moisture well and dry rapidly, although synthetics can retain body odor and can smell bad in a short time, and odor builds if they are worn more than once over a multi-day trip. Some synthetics even retain this odor after washing. Recently, many manufacturers have begun using Agion and other antimicrobial treatments to combat odor. Synthetics designed specifically by outdoor manufacturers (and some higher end sports synthetics) are significantly better than inexpensive sport synthetics, which generally do not breathe well.

Merino wool has become increasingly popular in the last 10 years or so, and has replaced traditional wool garments due to its superfine fibers which do not itch and are soft and comfortable next to the skin. Merino is warm, breathable, wicks efficiently (both through the core of the fiber and mechanically through the weave) and dries quickly (although not as quickly as synthetics). Major advantages of Merino are its natural ability to combat odor and the fact that a given weight and thickness of Merino is more efficient at regulating body temperature than synthetics. Unlike regular wool, Merino is a superfine (roughly 18 micron) fiber which does not itch, and is capable of moving moisture in the vapor state as well as in the liquid state like synthetics, although it is more expensive than most synthetic materials and is not as durable. In my opinion, the advantages outweigh the disadvantages, but even with Merino in your kit, the synthetics still have an important place, as described further below.

Other options for natural materials are bamboo and silk. Bamboo wicks, breathes, and regulates temperature well, does not retain odors, and has a good feel next to the skin. Bamboo is often blended with cotton or Merino wool in base layer garments. I do not personally have experience with bamboo base layers. Silk feels really good next to the skin and regulates temperature well in cool environments (although not as well when it warms up, and it can be uncomfortable in hotter weather or in the direct sun on a warm day), but it wicks more slowly and absorbs moisture so it takes longer to dry. Silk is often treated with chemicals to enhance wicking ability, which are gradually removed by washing so this capability is reduced as the garment ages. Silk is generally less durable than Merino and definitely less durable than synthetics. I had a set of lightweight silk underwear which was excellent next to the skin in colder weather, but it deteriorated in its second season.


Coyote Pounce 6791

A coyote performs his characteristic stiff-legged pounce to catch a vole who is hiding
in the brush and snow alongside Obsidian Creek near Obsidian Cliffs in Yellowstone.

Base, Mid and Insulation Layers, Shirts, Pants and Outerwear

Often photographers have to hike in to a location, then set up and wait for the dawn or wildlife, or wait for the light to be right. This means that there are often periods of strenuous activity where you are carrying significant weight followed by periods of inactivity, when your body cools down. Considering some locations can have pre-dawn temperatures below zero degrees F. (enhanced by a wind chill) followed by mid-day temperatures which can be 50 to 60 degrees warmer (it is not uncommon for temperature swings to exceed 60 degrees at high altitude or higher latitudes), your clothing selections have to reflect this and it is often best to use a larger number of lighter layers for adjustment of body temperature, which also gives you more options for different temperature ranges.

Like many people, I have built up a collection of garments over time, and due to their durability, most of the ones I liked are still with me. The garments which I did not like I gave away, and a few were damaged in use due to punctures or rock abrasion or simply wore out. Due to the tendency of synthetics to build up odor, I would generally carry several changes for multi-day trips, and have developed a feel for which work best in combination with each other. Lately, the use of Merino wool and current synthetics has reduced the number of changes which I have to carry, and this has allowed me to carry a smaller pack, which is a significant positive side effect which greatly offsets the additional cost of acquiring Merino wool or new synthetics. Below I will outline the various products I have selected and describe how they can be used in combination with each other. Keep in mind that selections are made from this group based upon the conditions for the location and the number of changes which will be required based on the length of the trip and the character of the materials.

You may wish to move directly to the Summary, or select a section from the Index below. Below the Index is a product list.


Layering Index



Base Layers: Synthetic and Merino

Field Shirts, Pants, and Outerwear

Legacy Synthetics

Summary and Recommendations

Product Descriptions

Product List

  —  Click a product title to jump to the Product Description, or click here for the Product Descriptions page. —

Sports Synthetics

Nike:  Pro Combat Hyperwarm Crew, Dri-Fit Performance 1/4-Zip, Pro Hyperwarm Special Field Fitted 1/4-Zip
Under Armour:  HeatGear Compression T-shirt, ColdGear Catalyst Crew, Sherpa Fleece Hoodie

Outdoor Synthetics

Patagonia:  Capilene 3 high neck 1/4-Zip Top, Capilene 1 silkweight bottoms (legacy versions)
                     Capilene 1 Silkweight Graphic T, Capilene 1 Silkweight Boxer Briefs
                     Capilene 2 Lightweight Zip-Neck, Capilene 2 Lightweight Bottoms
                     Capilene 3 Midweight Zip-Neck, Capilene 4 Thermal Weight 1/4-Zip Hoody

North Face:  Warm 1/4-Zip Mock Neck

Terramar:  TXO 2 midweight bottoms

REI:  midweight polyester Crew Top, Polartec 100 Teton fleece pants
Ex Officio:  Give-N-Go Boxer and Boxer Brief

Merino Wool

WoolX:  X303 160 g/m X-Lite Boxer Briefs, X302 Outback 170 g/m Lightweight T-shirt
               X304 Base Camp 160 g/m Lightweight Long-Sleeve T-shirt, X305 Base Camp 160 g/m Lightweight Hoodie
               X507 260 g/m Explorer Midweight 1/4-Zip Top, X509 230 g/m Explorer Midweight Bottom
               X704 400 g/m Blizzard Expedition weight 1/4-Zip Top

Smartwool:  250 g/m Merino Funnel Zip Top, MerinoMax Heavy-Midweight Half-Zip
                     195 g/m Merino Boxer Brief, 150 g/m Merino Boxer Brief

Patagonia:  Merino 1 Silkweight T-Shirt, Merino 1 Silkweight Boxer Briefs
                     Merino 2 Lightweight Zip-Neck, Merino 2 Lightweight Bottoms
                     Merino 3 Midweight Zip-Neck, Merino 3 Midweight Hoody

Icebreaker GT200 Sprint Long Sleeve Crew (and Aero Crewe featherweight short-sleeved T-shirt)
Mountain Hardwear Integral Pro Long Sleeve Crew
Uniqlo Extra-Fine Merino Crew-neck Sweater

Field Shirts and Pants

North Face:  Cool Horizon Long Sleeve Shirt
Ex Officio:  Air Strip Long Sleeve Shirt
Mountain Hardwear:  Canyon Long Sleeve Shirt (and Chockstone Midweight Softshell 3/4 Pants)

Arc'teryx:  Bastion Pants
North Face:  Paramount Peak Convertible Pants
Kuhl:  Krux Long Short, Rydr Pants, Kontra Air Pants, Radikl Pants, Raid Softshell Pants

Patagonia:  Venga Rock Knicker
Stonemaster:  Stonemaster Knicker, Nirvana Knicker, Herringbone Knicker
Endura:  Hummvee 3/4 Pants


Patagonia: Torrentshell Pullover
Marmot:  ROM hooded Soft Shell Jacket, Precip Full Zip pants
Mountain Hardwear:  Hard Shell DWR Jacket (earlier model similar to current Ampato, with ReviveX DWR coating)


Mountain Hardwear:  Power Stretch Polartec Beanie, Pacer Running Cap
Prana:  Mojo Camper Cap


Dave’s Run with UFO 4649

Dave’s Run from the top of Mammoth Mountain at over 11,000 feet, on a cold and windy Christmas afternoon.
It was 10 degrees below zero with a forty mile per hour wind chill and I rapidly took several images, not seeing
the UFO which appears in this image until later, when I was processing the RAW file (UFO is in the upper left).

This image caused quite a furor, especially amongst the UFO community. I have no idea
what it is, but I was able to find out that there were no reported weather balloons in the area.


Click to move on to the Legacy Synthetics page.


Click to move on to the Base Layers page.


Click to move on to the Outerwear page.


Click to move on to the Summary page.


Click to move on to the Product Descriptions page.