Icebreaker

Almost every Icebreaker product has a number in its name. That number is roughly the weight of the fabric in grams per square metre, so it tells you how warm and how heavy the garment is before you know anything else about it. Get the number right and the rest of the choice is mostly about cut and sleeve length.

Hot weather and travel: 150

Icebreaker call this weight Ultralight, and it is thin - closer to a good cotton t-shirt than to a thermal. It is the weight to buy for summer walking, for a shirt that lives in a carry-on, and for anyone who runs warm. The trade-off is honest: light merino is the most comfortable fabric here and the least hard-wearing, and it wears through first under a pack's shoulder straps and hip belt. If you're carrying a loaded pack most days, go up a weight.

Most of the year: 200

The 200 weight - Lightweight in Icebreaker's naming - is where most people should start, and the Oasis is the piece the rest of the range gets compared against. It is warm enough for a cool morning under a jacket, thin enough to wear on its own into the afternoon, and it works as a base layer under snow gear without adding bulk. If you're buying one Icebreaker item and you don't know yet what you want it for, buy this one.

Snow and genuine cold: 260

Midweight, and it feels like it. The 260 pieces are built for snow trips, alpine walking and cold-climate travel, and for most Australian winters outside the mountains they're more than you need. Bought for the wrong conditions, a 260 top is the one that stays in the drawer.

Warm mid layer: 300

The heaviest weight in this guide, and it turns up in the RealFleece mid layers rather than in anything worn against the skin. At 300, this is the layer that goes over a base layer on a cold day, or under a shell when the wind picks up.

In short: 150 for summer and travel, 200 for the rest of the year, 260 for the snow, 300 for a warm mid layer.

Socks are the biggest part of what people come to Icebreaker for, and the choice comes down to how much cushioning sits underfoot and how high the sock sits on the leg. Everything else - the wool, the odour resistance, the shaping - is common across the range.

Day walks and warm weather: Hike+ Light

The lightest of the hiking socks, with thin cushioning under the foot and enough merino to stay comfortable on a long day. It is crew height, so it sits above the ankle and works with low-cut shoes as well as lighter boots. There's an Icebreaker Merino Hike+ Light Crew Womens Socks and an Icebreaker Merino Hike+ Light Crew Mens Socks.

Boots and multi-day walking: Hike+ Medium Crew

The same crew height with more cushioning underfoot, which is what you want with a boot and a heavier load - the cuff sits above the collar so the boot isn't rubbing bare skin. The Icebreaker Merino Hike+ Medium Crew Mens Socks is the one to buy if you're walking in boots with weight on your back.

Running: Run+ Ultralight Mini

Thin, low-profile and shaped for a running shoe. The Icebreaker Merino Blend Run+ Ultralight Mini Mens Socks is a merino blend rather than pure wool - the nylon and elastane are there so the sock keeps its shape through a lot of washes, which pure merino at this thickness does not.

Ski socks are a different shape again: tall enough to come over the calf and deliberately thin through the shin, because padding inside a ski boot causes more pressure points than it solves. Worth knowing before you put hiking socks in the ski bag.

In short: Light Crew for day walks and warm days, Medium Crew for boots and load, Run+ for running, and something taller and thinner for ski boots.

This is the part of the range people buy once and then come back for. A merino tee is worth the money over a cotton one for the same reason it's worth it over a synthetic one: it doesn't smell after a day's wear, so it travels well and washes less.

The everyday tee: Tech Lite III

The 150-weight Tech Lite III is the plain short-sleeve tee, and it's the piece that does the most work in most people's wardrobes. It's cut looser than the base-layer tops, so it wears as a normal t-shirt rather than as gear.

Hot and humid: Cool-Lite

Cool-Lite is merino blended with plant-based fibre, and the blend is noticeably cooler and stretchier than pure wool at a 125-weight. It's the better choice for summer in the north or for anywhere the humidity does more damage than the temperature.

Thermals are where the weight number matters most, because the difference between a 200 and a 260 is the difference between a layer you can wear all day indoors and one you can't.

The year-round base layer: 200 Oasis

The Oasis is Icebreaker's best-known piece and the one to default to. The Icebreaker Merino 200 Oasis Long Sleeve Crewe Thermal Womens Top and the Icebreaker Merino 200 Oasis Mens Merino Thermal Leggings are the two to start with. A 200 top and leggings worn together will cover most cold-weather trips on their own. Kids get the same fabric in the Icebreaker 200 Oasis LS Crewe Kids Thermal Top.

Cold mornings and snow: 260 Tech

The Icebreaker 260 Tech Mens Merino Long Sleeve Half Zip Thermal Top is the warmer version of the same idea, and the half zip is the useful part - it lets you dump heat on the way uphill without stopping to take a layer off. If you're choosing between the two and the trip involves a chairlift, take the 260.

Working hard in the cold: ZoneKnit

ZoneKnit puts open, more breathable panels where you sweat most and solid fabric everywhere else, so it stays comfortable at a higher effort level than a plain knit does. The Icebreaker ZoneKnit 260 Womens Leggings and the Icebreaker ZoneKnit 260 Mens Leggings are seamless for that second-skin feeling.

In short: 200 Oasis unless you know you need more, 260 Tech for snow, ZoneKnit if you're the person who overheats.

Merino mid layers do a different job to fleece. They're warmer for their weight than they look, they don't hold smell after a week of wearing, and they're quieter and less bulky under a shell.

The one that gets bought most: RealFleece Descender

RealFleece is merino brushed on the inside so it behaves like a fleece, and the Icebreaker Merino Blend 300 RealFleece Descender LS Zip Mens Jacket is the piece people come looking for by name. It has mesh panels under the arms, which is why it works for walking uphill rather than only for standing around at the top.

This is the quiet strength of the range and the reason a lot of people buy Icebreaker at all. Merino underwear is the single best argument for the fabric: it stays wearable for far longer between washes than cotton or synthetic, which is why it turns up in every long-trip packing list.

Men's: Anatomica

The Icebreaker Merino Anatomica Mens Boxer Briefs is the standard fit, and the Icebreaker Merino 150 Anatomica Mens Long Boxers runs longer in the leg, which stops the chafing you get from a shorter cut under a full day's walking. One thing to know before you order: for hygiene reasons we can't accept returns on underwear, so check the size guide first rather than buying two sizes to try.

Women's: Siren

The Icebreaker 150 Siren Womens Merino Padded Bra is a light-support bra in the 150 fabric, with adjustable straps and removable cups so you can set the fit rather than take what you're given. It's the one for travel, flights and everyday wear rather than for running. It isn't a high-support sports bra, and it's worth being clear about that up front.

The Siren briefs come in two cuts, both in the same 150 fabric with the merino spun around a nylon core - which is what stops them wearing through, because pure merino this thin wouldn't survive a season of washing.

The difference between the two is rise. The Siren Hipkini sits higher on the hip, with low-profile elastic at the waist and leg openings. The Siren Bikini sits noticeably lower and cuts closer. Both are cut slim and run true to size, so take your usual size.

Merino accessories are the cheapest way into the fabric and the things most likely to get lost, which is a fair reason to buy the reversible one.

Everyday warmth: the Icebreaker Beanie

The Icebreaker Merino Icebreaker Beanie is double-layered and reversible, in a merino and organic cotton blend rather than pure wool - softer against the forehead, which is where most people find out whether they can wear wool on their head or not.

Gloves you can use a phone in

Both of ours have touchscreen fingertips. The Icebreaker RealFleece Merino Sierra Unisex Gloves use the same brushed merino as the Descender and are the warmer, softer pair. The Icebreaker Quantum Merino Gloves are thinner with silicone grip on the palm, which makes them the better liner glove under a ski mitt or the better choice on the bike.

Neck gaiters and balaclavas sit with our other balaclavas and neckwear, and the rest of the hats are under beanies.

Tops: t-shirts, thermal tops, hoodies and sweatshirts, jackets, vests, singlets, bras

Bottoms: thermal bottoms, tights, pants, underwear

Socks and accessories: socks, beanies, gloves, balaclavas and neckwear

Heading somewhere cold and not sure what goes in the bag? Our guide to what to pack for a Japan ski trip runs through a full layering system, base layer up.

Shipping is free Australia-wide on Icebreaker, with bulky items excluded, and you have 80 days to return anything - sale items included. The exception is underwear, which we can't take back for hygiene reasons. Full detail is on our shipping and returns pages. If you'd rather try things on, both our stores carry the range and you can collect an online order from either; addresses and hours are on our store locations page.

What size Icebreaker should I get?

Icebreaker sizes in S, M, L and so on, and they run close to standard Australian sizing - most people take the same size they'd take in a normal t-shirt. The thing to watch is the cut rather than the number: the base layers are slim-fit and sit close to the body by design, while the Tech Lite tees are cut looser. If you're between sizes and buying a base layer, take the smaller one, because a loose base layer doesn't do its job. Our Icebreaker size guide has the measurements.

Does Icebreaker have a warranty, and who handles it in Australia?

Icebreaker warrant their gear against manufacturing faults, and the terms vary by product line. If something you bought from us fails, contact us and we'll handle the claim for you rather than sending you to the brand. Your rights under Australian Consumer Law apply on top of any warranty the brand offers.

How do I wash merino?

Machine wash cold on a gentle cycle, no fabric softener, and line dry in the shade. The two things that shrink merino are heat and agitation, so a tumble dryer is the fastest way to ruin a good base layer. You'll also wash it far less often than you're used to - most people find a merino tee goes three or four wears between washes and airing it out overnight does most of the work.

Is Icebreaker warm enough for the snow?

As a base layer, yes - a 200 or 260 top and leggings under a shell is a standard snow setup and it's what most of the range is designed for. Merino handles the wet-then-cold cycle of a snow day better than cotton and stays comfortable when you sweat on the way up. What it isn't is an outer layer: you still need something waterproof over the top. If you're heading to Japan, Canada or Europe for their winter, the 260 pieces are the ones to pack.

Can I return merino underwear if it doesn't fit?

No - underwear is the one exclusion from our 80-day returns, for hygiene reasons. Check the size guide before you order, and if you're unsure, buy one pair first rather than a multipack.

Does Icebreaker make kids' sizes?

Yes, though the kids' range is much narrower than the adult one - mostly base layers in the same 200 Oasis fabric. The Icebreaker 200 Oasis LS Crewe Kids Thermal Top is the piece most families start with.