What is a Base layer?

Whether it’s a baselayer or a base layer, it’s a relatively new term!

A base layer is what you wear next to your skin, often as part of a layering system.  Your ‘first line of defence’ normally against cold, but also applicable in the heat.

Base layers need technical functionality. warmth, but with breathability, ideally moisture managing, so if you do sweat in cold weather (best avoided, “start cold”!) it doesn’t leave you wet and cold and vulnerable when you stop.

A layering system delivers temperature control and comfort; warmth gets trapped in the layers, which can then be removed if you’re working hard.  Cellulosic fabrics, with lots of little micro pockets of air which get trapped and warm up next to your skin, are ideal.  For example, wool, and also bamboo.


In extreme heat obviously a base layer’s breathability and comfort are all important, as well as its ability to manage moisture, all in the name of keeping you as comfortable as possible.

BAM offers base layers for men and base layers for women for operating comfortably in the heat and cold.  We passionately believe BAM base layers are the best you can have next to your skin, delivering comfort and versatility.  The fabric is incredibly soft next to your skin, but delivers all the functionality required to keep you comfortable at all times, as part of a layering system.

A base layer is not just a top, it can also be your leggings and underwear.  Tops can be either short or long sleeved and can be with or without zips.

As a base layer in very hot conditions, overwhelming feedback from expedition leaders and adventurers tells us that BAM underwear, T-shirts, socks, baselayers are world class pieces of kit to have in your bag.  

For example, Ali Wilde, expedition leader for Secret Compass said of our men’s sports boxers (underwear) after a 16 days non stop trek through tropical rainforest in Madagascar:

“brilliantly comfortable and wicking so didn’t have any problems with the heat and exertion.  I would thoroughly recommend them to anyone”

In the cold You need versatility, comfort, warmth when you’re standing around, breathability when you’re working. This is BAM, as Andy Harvey, Operations Director of Extreme World Races said at the Magnetic North Pole:

“Brilliant bit of kit, which I’ll use on all company and personal trips in future”

From BAM founder, David Gordon:

“In 2004, the year before I discovered bamboo clothing, I found myself crossing Greenland with a British Army expedition.  It involved manhauling 100kg uphill for 300km then downhill for 300km.  after 3 weeks of this my feet were in bits, in poorly fitted boots – note to self…:)  – multiple blisters, sores, bruised heel, frostnip, trench foot and general fatigue, but oddly the one condition I wanted to change above all else was a small itch in a difficult to reach place on my back.  Just a tiny little irritating, annoying itch from my wool base layer.  That’s always struck me as ironic…”

BAM Runner

What material is best used for a base layer?

Now we are a little biased but, hopefully we may be able to give you a few reasons why a blend of fabrics with bamboo at its core is best.  Our Bamboo base layers are made from 68% Bamboo Viscose, 28% Organic Cotton and 4% Elastane. 

Merino Wool is often touted as the best for base layers, it is a great product but many wearers raise concerns due to the itchy nature on the more cheaper options, while Merino trumps cotton for moisture managing (cotton just likes to draw it in and make you damp and then smell which isn’t nice at the best of times) bamboo excels in being much softer as well as keeping you dry being 3-4 times more absorbent as cotton.  The nature of bamboo makes it very absorbent and effectively manages moisture away from the skin and because it is very breathable allowing you to stay cool or warmer on colder days when needed.

Synthetic materials are also well regarded but if you, like us also care about your environment then nothing beats naturally grown bamboo. Bamboo also has many other benefits which you can see here


When should I wear a baselayer?

A baselayer can be very versatile and should be snug, but not too tight and ideally next to your skin to keep you warm or cool, pretty amazing stuff really! 

If it’s a little colder then you should consider wearing more than one baselayer, the more layers then heat becomes trapped and the warmer you will get, although we don’t recommend adding so many that you cannot move!  With a UK climate and depending on conditions we would recommend one or two baselayers with the addition of a sweat, fleece or waterproof jacket in the colder months. In the warmer months our short sleeved baselayers are ideal as they also benefit from UV protection due to the bamboo properties.

Whether you are skiing, running, doing yoga or simply walking a baselayer is an essential piece of clothing whatever the exercise.