Skip to content

Why Merino Wool Base Layers

Why you should consider using Merino Wool Base Layers and the advantages of doing so.

So what are the benefits of choosing a Merino Wool Base Layer over a Synthetic option? First and foremost, Merino Wool is, of course, a naturally occurring fibre.  Merino Sheep produce Merino Wool and because merino sheep evolved in extreme cold, they developed a wool fleece that is extremely fine and very durable. Equally, it is also relatively rare compared to those sheep you see on the hills in the countryside.  True Merino sheep, live on high ground, and it’s this environment that gives Merino it’s unique properties.


Merino Wool Base Layers are therefore naturally breathable, like a direct extension of your skin, and therefore make for excellent next-to-skin layering.  They are also naturally insulating and odour resistant. Because of the fibre used, Merino Wool Base Layers have some unique properties that allows your body to keep you thermally regulated in a wide range of temperatures and conditions.

Merino Wool fibres are much finer than other wool fibres due to the evolution of Mother Nature. Merino Wool fibres are less than 24 microns in diameter (roughly a 10th of the width of a human hair). Most of our Merino Wool Base Layer ranges have a 16-18 micron diameter making them very fine and soft next to the skin. The weight of the fabric produced is measured in grams per square metre (gsm) – this is usually a good indicator for how warm the base layer is.  The bigger the GSM weight…..the warmer they will be.  Most Merino Base Layers will max out at 260-300GSM.

Merino wool is in reality, a “living fibre” that adapts to your environment and body temperature. All natural fibres can absorb and eradicate moisture, but Merino Wool is particularly good at doing so.


Merino Wool does this by absorbing excess moisture and vapour into its physical structure but retains the ability to expel that moisture back into the atmosphere. This unique natural ability helps to keep your body temperature regulated for warmth and cool by this evaporation of moisture process called “wicking” which cools you down if you begin to overheat.

Merino Wool fibres can absorb up to 5x their weight in water before feeling damp to the touch. When your Merino Wool Base Layer can’t absorb any more moisture, its fibres will wick the moisture away to ensure your skin remains dry and you do not get cold.

This naturally breathable capability of Merino Wool means it can control the rate of evaporation much better than many synthetic options. Merino Wool releases moisture quickly when your body surface is hot and damp, and slows down when it’s cold and dry.  Merino Wool Base Layers will still work effectively as a thermal insulator, even when wet.

Merino also reacts with water in a unique chemical process and, in effect, uses that water to create a chemical reaction that releases heat. This chemical process acts as a defence against excess rapid cooling if you get sweaty after a hard climb or ride for example.


Merino Wool is naturally insulating.  There’s a very good reason sheep wear it! Merino Wool fibres have a unique shape which captures heat in insulating air pockets, so when these are layered together, you get this natural electric blanket effect. The finer the Merino fibre, the wavier it is, and the more air pockets it can create. This gives Merino Wool an excellent warmth-to-weight ratio, something often used in the descriptions of Merino Wool Base Layers.

It is because of the unique structure of Merino Wool fibres that they don’t lose the ability to keep you warm even when wet as these pockets of trapped warm air provide thermal insulation even when damp.

Next to skin comfort is of course critical in any base layer and because Merino Wool fibres are so fine, they are softer than standard wool and therefore do not cause any itching on the skin in 99% of situations. Maybe because Merino Wool is nature’s natural insulator, Merino Wool Base Layers feel more luxurious next to the skin as well.

Merino Wool Base Layers as explained, absorb a large amount of moisture before the fabric starts to feel damp and so rarely feel uncomfortable against the skin.

One other major factor with a Merino Wool Base Layer is that Merino wool is naturally odour resistant.  This is due to the natural Lanolin in the fibre that Mother Nature has created that allows Merino Wool to resist bacterial infestation so well.

Unlike synthetic base layers which need a treatment of some sort to help eradicate those human smells we all create; Merino has its own unique ability to keep nasty niffs at bay……naturally. By keeping your skin surface dry, Merino reduces the growth of odour-causing bacteria in the first place. But wool also traps odours inside the fibres itself only releasing them when the garment is washed. Additionally, research has also shown that Merino fibres provide a less hospitable environment for bacteria to survive than synthetics.  But when you do wash your Merino Base Layers, don’t use a fabric softener……it will reduce the ability of your Merino Base Layer to perform to its optimum level.

Perhaps the most important consideration given our modern world is that Merino is also Biodegradable which makes it good for the environment as it has low to no environmental impact. As a natural fibre, Merino wool will biodegrade under the right conditions after disposal rather than hanging around in the environment for many years like man-made synthetics.

Your Merino Base Layer is also Fire Retardant which most people don’t realise. Merino wool is naturally flame resistant. This means that it will not melt or stick in the event it, or you, are exposed to high heat or naked flames.