When you’re getting ready for adventure you have all sorts of choices about what kind of base layers to buy. And, of course, every different company is out there telling you why theirs are the best. So how do you know who to believe?

Well, the truth is, we’re happy to admit there are plenty of other good base layers out there. (And even more not so good ones!) So sometimes it simply comes down to budget and what’s really important to you. And just how good you want your base layers to be.

Here’s one thing just about all experts agree on though: Merino is easily one of the best possible fabrics for cold weather. Cotton gets called ‘Killer Cotton’ for a very good reason – in extreme conditions you will freeze to death in it. And while some synthetics can do the job, they often come with other serious compromises.

So let’s assume you’ve done what all smart adventurers do, and decided on Merino thanks to all the natural benefits it delivers (which you can read about here). How do you decide which particular Merino thermal base layers to buy?

Let’s start with the first basic truth:

Truth 1: Not all Merino fabrics are created equal.

Just like not all shoes or backpacks or GPS watches or cars are created equal, there are all kinds of Merino. From coarse, scratchy Merino through to superfine, super warm and comfortable Merino like our exclusive MicroMerino® fabrics. This isn’t some fancy name for a technical difference that you’ll never even notice. This is Merino made from thinner, smoother fibre that makes the fabric feel much softer and smoother against your skin. Touch our fabrics, and touch their fabrics, and you’ll instantly feel the difference. The truth is, we don’t really believe in compromise. If you’re with us on that one, chances are MicroMerino® is what you’re looking for. After all what’s the point of being super warm if you’re not also super comfortable?

Truth 2: Our founder is a man with a mission.

David Michell is a 6th generation wool man. So what he doesn’t know about wool isn’t worth knowing. His family have been working with wool since not long after sheep were invented, and he’s made it his personal mission to create the world’s most comfortable, best performing Merino fabrics. The result of all his hard work is MicroMerino®.

Michell Factory workers in Adelaide, South Australia, 1870

The Beginning: Michell Factory workers in Adelaide, South Australia, 1870


Some would say he was ‘obsessed’, we prefer the word ‘passionate’. This is a guy that skis the slopes, treks the trails and has even run the brutal North Face 100km trail race through Australia’s Blue Mountains. So he’s not some guy sitting back in a posh office just talking the talk, he’s out there running, skiing and walking the walk. And if it’s not good enough for him, it doesn’t see the light of day. When you see the I/O Merino name, just imagine David standing right behind it giving it the big thumbs up.

Truth 3: The facts. And figures.

To start with, our exclusive MicroMerino® fabrics use only the finest Australian Merino wool – that’s the Merino wool that’s universally acknowledged as the best in the world. Australia may not ever win the space race, and some of our sports are incomprehensible to the rest of the world, but when it comes to wool, our sheep are hands down the best on the planet.

Our MircoMerino fabrics start here – with the world’s finest Merino wool

For our fabrics, we use 18.5 micron wool which officially falls into the ‘superfine’ classification. And while others claim a similar micron measurement, it’s worth noting there are several other variables in the production process that effect the overall quality and feel of the fabric. We won’t bore you with too many details, suffice to say things like the quality of the original wool, how many times it’s twisted to create the yarn, and how that yarn is knitted into fabric all contribute to how good the finished product performs and feels.

Plenty of people make Merino, but getting it right every step of the way to create the perfect combination of softness, durability and comfort really is part science, part art form. And one we’ve pretty much perfected. We even had actual white-coat wearing scientists help us develop our MicroMerino® fabrics. Combine that with David’s family know-how and experience, and we can honestly, albeit somewhat immodestly, claim to have produced a Merino fabric that is so fine, soft, warm and comfortable that it sits in a league of its own. The MicroMerino® League.

Truth 4: We don’t just say it’s the best, we guarantee it.

We’re completely fine if you don’t believe a word we say. Why would you? Talk is cheap, right? So here’s our challenge to you. Buy one of our products. Try it on. Not just in a change room somewhere where anything can feel good for all of 30 seconds. But really try it on and try it out. Get out there in the elements. Hike in it. Climb in it. Ride in it. Ski in it. Do whatever you do in it. For up to 60 days. And if at the end of those 60 days, you don’t agree with us, and plenty of experts, who say ours is some of the most comfortable Merino you’re ever likely to wear, simply send it back for a full refund. We call it the ‘Absolute Love Guarantee’ because we’re so confident you’ll absolutely love it, we’re prepared to give you your money back if you don’t.

So, what have you got to lose? If quality matters to you, whether your life depends on it or just your comfort, and you’re not the kind of person who likes second best, choose MicroMerino® – exclusive to I/O Merino on planet Earth.

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