The base layer is an important part of your layer system because it is the layer that will control your comfort level. The performance of the base layer can be the difference between being comfortable and uncomfortable. Get the base layer wrong and you limit the performance of the layers above it.
What base layers should I buy? Cooling or thermal? And during what seasons should I wear them?
The primary role of any base layer is to control the microclimate next to your skin by moving moisture away from your body. A secondary role relates to either trapping or removing the metabolic heat your body generates.
During Summer you want this heat to be able to escape through a combination of removal of trapped moisture, and airflow for evaporative cooling. Ice Dry fabric with zoned mesh panels uses capillary action to draw moisture off the surface of your skin transferring it to the surface of the fabric. This is done without the addition of wicking chemicals, that only have temporary effectiveness, guaranteeing you will as be as cool and comfortable at the end of summer as you were at the beginning.
Winter base layers should still transfer moisture off your skin, but the secondary role is to trap the heat, holding it next to the skin acting as your first thermal layer. Merino wool for example is excellent at this, with the ability to draw moisture without huge loss of thermal ability.
Are your base layers synthetic or natural?
If you are going to sweat a lot because of activity or climate you need to wear a synthetic base layer. Performance Polyester absorbs only around 0.4% of its own weight in water and thus dries very fast, while also efficiently wicking moisture away from the skin to spread it on the outside of the fabric where it can be pulled away by evaporation keeping you cool and dry. Cotton fibres are hydrophilic and will soak up moisture and store it in the cellular walls of the fibre holding the damp wet fabric against your skin.
Merino is a natural fibre that does a better job than cotton of removing moisture from your skin This is possible because only the inner part of the merino fibre absorbs water while the outer part which lies against your skin stays dry. Therefore, merino wool base layers efficiently eliminate the conductive heat loss. However, the dry times and low durability of super-fine merino are issues. Merino is thermal and naturally odour fighting, but polyester is lighter, stronger and dries faster than merino wool. So, the fusion of merino and polyester in the Thermal Dry base layer range creates the ultimate cold weather base layer.
My rain jacket seems to be leaking as my cotton T-shirt is always soaked after wearing my jacket. Why is that?
The capillary action of cotton will pull moisture from the body and but rather than transfer it to the surface of the fabric like Ice Dry, it will hold it in the fabric making your tee shirt water logged. The thermal conductivity of water is much higher than the thermal conductivity of air. If your apparel gets soaked with sweat, your body heat is rapidly transmitted to it through conduction and you lose warmth rapidly. Waterproof breathable rainwear relies on the pressure differential created by warmth inside driving moisture vapour outside towards the cold environment. Because the cotton has robbed your internal micro-climate of this ability, the moisture is able to build up and you will feel wet and cold even if water is not penetrating your outer layers.
How many base layers should I take with me on my hunting trips?
The sensation of comfort is felt at a skin level, if your skin is wet and cold, you will feel wet and cold no matter what layers you have on top. So, a dry base layer is the fastest way to return heat into your system, conversely your body will be very slow to heat if you have wet layers next to your skin. Carrying a spare base layer to switch out at appropriate times can be a game changer. Consider at the end of the day how you are going to dry any moisture out of your wet base layers for the following day.
As you can see, there is a lot to consider when choosing the most appropriate base layer garment for your next hunting application. Rather than neglecting your next-to-skin layer or choosing fabrics that may not perform to the conditions, we recommend spending some time to understand the hunting application first and then finding the correct balance of performance attributes that will maximise your experience throughout the entire duration of your trip, whether that is a quick afternoon hunt throughout the seasons, or a 10-day expedition into the backcountry where minimum weight, quick drying performance and compact volume are huge decisions you have to make when selecting what gear to take. Having a good understanding of your gear, how it performs, how to layer accordingly, and how to maintain your garments to get the best out of them is crucial. Treat your technical apparel with as much care and maintenance as you do your rifle or optics and it will take care of you when out in the mountains or the forests.
