How to choose a Thermal Baselayer
Want to have a comfort boost on your next outdoor adventure?
Invest in a moisture wicking baselayer garment (also known as first layer) for the ultimate comfort experience. Leave the cotton t-shirt at home, it may look cool, and cool is exactly what you will be once you start to exert yourself.
Moisture wicking undergarments can benefit any physically active person - from athletes to outdoor workers and is a must for every outdoor adventurer, no matter what the season. As the next-to-skin layer of any layering system, it's number one role is to move moisture away from the body.
Here at Anaconda we have three brands that provide these first layer garments:
37 South Baselayer
Shop With Anaconda for 37 Degrees South Baselayer
Cape Polypro, a lightweight, high-wicking, synthetic, breatheable garment
Shop With Anaconda for Cape Polypro
Cederberg Merino, made from 100% Australian Pure Merino Wool
Shop With Anaconda for Cederberg Merino
|37 South Polyester||Cape Polypro||Cederberg Merino|
Polyester is not a great wicking fabric and as such will absorb water faster.
Non-absorbent fibres transport moisture away from perspiring skin, spreading it over a large area of the garment's outer surface to speed evaporation.
The inner code of the Merino fibre absorbs moisture (up to 36% of its weight), and then gradually releases the moisture through evaporation.
Not a lot of difference in drying time.
Dries faster than any other thermal fabric.
While slower to dry than Polypro, Merino fibres have an outer sheath that resist water and often feels dry on the skin.
Polyester has a higher heat transfer rate than polypro.
In hot, humid climates the faster drying Polypro is usually a better choice.
Merino offers more warmth than a synthetic garment of the same thickness.
Polyester is a very snug fitting fabric, and the shape will not deteriorate after many washes and wears.
Due to lightness of the yarn, polypro does have a tendency to lose shape after a number of wears.
Some protection offered
Definitely requires washing after each use.
It is better for all concerned if washed after every use.
Merino garments can be worn on consecutive days without a wash making it perfect for long hikes.
Cape Polypro is very moderately priced.
However, because it can be worn consecutively, it becomes a very economical purchase.
Light exercise such as walking, fishing.
Fantastic for Autumn/Spring conditions.
All activities, all conditions.
Best for rainy conditions and heat and humidity.
Snug fit best for cold weather, loose fit for warm.
Most activities, most conditions.
If paddling or in rainy conditions faster drying Polypro may be better option.
Perfect for cold weather and alpine conditions.
Wicking - Cape Polypro & 37 South Polyester
- During active exercise, a person wearing a Polypro or Polyester garment begins to sweat.
- A high humidity micro-climate is created between the person’s sweating skin and the garment covering the skin.
- Perspiration vapour and moisture condense on the garment’s interior.
- Because everything in nature moves towards equilibrium, the high-humidity air mass between the skin and garment will seek a path to a lower humidity environment. The difference between temperature and humidity on both sides of the garment become the driving force that moves the warmer, wetter air beneath the garment towards the cooler, dryer air on the outside.
- Wicking takes place when the perspiration moisture travels along the surface of the fibre but is not absorbed into the fibre. Polypro and Polyester, like most synthetic fibres, are generally plastic and virtually non-absorbent. Moisture escapes to the outside through the interstitial spaces (the minuscule holes) between the knitted yarns.
- Moisture is dispersed across the fabric’s exterior, where it evaporates after contacting the lower humidity environment outside the garment.
Wicking - Cederberg Merino
Technically Merino does not wick moisture. The end result, however – fibres moving moisture away from the skin and dispersing it through evaporation – is the same.
Rather than straining perspiration moisture and vapour through the minuscule gaps in a non-absorbent knit, Merino’s inner core (cortex) absorbs moisture up to 36% of it’s weight.
This absorbed moisture is then impacted by the lower humidity, air movement and (potentially) sunlight on the outside of the garment. The result: evaporation.
With so much moisture being absorbed, will a Merino garment feel soggy? If it becomes saturated and is confined to a damp or high-humidity environment, it could.
|Yet wool has the capacity to both absorb moisture (in a vaporous state such as perspiration) while also resisting water (in a liquid state such as light rain). This is one of the almost-too-good-to-be-true characteristics of Merino. Merino fibres have a scaly exterior layer called the cuticle, and that is overlaid with the epicuticle, which is coated with lanolin, a waxy, water shedding film. It is the epicuticle and it’s waxy coating that makes Merino resistant to mist and light rain (hydrophobic). It is this hydrophobic layer that touches your skin, minimizing (or eliminating) any sensation of dampness.|
Merino and Temperature Regulation
Some people may be hesitant to wear Merino as a next-to-skin layer due to the perception that Merino wool is scratchy and coarse. This is not the case at all. Cederberg Merino garments use 100% Australian Fine Merino wool with fibres measuring just 20.5 microns in diameter. For comparison, the average human hair has a diameter of 100 microns. Cederberg Merino is luxuriously soft and smooth against the skin.
A property unique to Merino is it's ability to release small amounts of heat as it absorbs water. This effect is known by the obscure term "heat of sorption". Energy, in the form of small amounts of heat, is produced through the work of moisture-absorption by the Merino fibres. So, in damp conditions, a wearer of Cederberg Merino could potentially collect a small amount of warmth from this process. This is in addition to the countless warmth-trapping air pockets created by all the crimps inherent in the Merino fibre.
Some may think that this process could make Merino too warm in hot conditions produced from physical exercise. This is definitely not the case with Merino. Evaporating moisture within the cortex can cool the air between the Merino fabric and your skin, promoting a stable body temperature. Also, the breathable Merino fibres can buffer skin from air heated by the sun or physical exercise the same way they can trap warmed air and keep it close to skin in cool conditions.