Fabric weight guide
Which merino weight is right for you?
GSM is grams per square metre — how much fabric there is, not a warmth rating. Every weight is the same soft 17.5-micron Australian merino: it wicks sweat before it turns cold, insulates when it is cold and ventilates when it is warm. Lighter fabric breathes and dries faster; heavier fabric holds more heat when you stop moving. Choose by season and by how hard you will be working.
Warm & hot weather · 60°F+ / 15°C+ — and high effort in any season
Best for: summer hiking, running, cycling, hot-climate travel, everyday tees and office wear; the next-to-skin layer under a 250 when you work hard in winter
Pick this if: you want a shirt that stays fresh for days, dries in an hour and keeps you cooler than cotton in the heat — or you simply run hot
Think twice if: you will mostly be standing still in the cold; on its own a lightweight layer has little insulation to offer
Shop 165 GSM →Cool to mild · 40–65°F / 5–18°C
Best for: spring and autumn as a standalone top, summer evenings, cool-morning hikes and commutes; winter as a base under a mid-layer
Pick this if: you want one merino layer that covers most of the year, or you are unsure between light and mid — this is where most people should start
Think twice if: you run cold and your winter is genuinely cold: go straight to 250
Shop 190 GSM →Cold · 20–45°F / −7–7°C — the classic winter base layer
Best for: skiing and snowboarding, winter hiking, cold-weather work, frosty autumn mornings; top-and-bottom sets so your legs are not the weak link
Pick this if: you run cold in fall, want the classic winter base layer, or spend active days below freezing under a shell
Think twice if: you overheat easily on hard uphill efforts — a 165 or 190 underneath, 250 over it, is the better system
Shop 250 GSM →Deep cold · below 25°F / −4°C — especially when you stop moving
Best for: ice fishing, hunting stands, camp at altitude, winter mornings spent waiting rather than walking, a house that never quite gets warm
Pick this if: warmth matters more than breathability, you are chronically cold, or your winter involves long spells standing still outdoors
Think twice if: you will be working hard — it is too warm for a sweaty climb, which is exactly the point
Shop 320 GSM →A base layer works by sitting close to the skin, where it can move moisture — loose is not more comfortable, just slower. Between sizes? Size down for a next-to-skin layer under a shell, size up to wear it on its own or over another layer. Merino stretches with wear and springs back after a wash. Heavier weight is not itchier: itch comes from coarse fibre, and every weight here is the same superfine merino.
Size guide
Size Guide
Our merino has a close, next-to-skin fit by design. If you are between sizes, stay true to size for base-layer use or size up for a more relaxed everyday fit. Free returns within 30 days, so ordering two sizes and sending one back is completely fine.
How to measure
Chest — around the fullest part of your chest, with the tape level under the arms.
Waist — around your natural waistline, with the tape comfortably loose.
Hips — around the fullest part of your hips and seat.
Inside leg — from the top of your inner thigh to your ankle bone.
Measure over light clothing, keeping the tape snug but not tight. Tap any chart below to open it full size.
Men's Base Layer Set
Need different sizes for the top and the bottoms? Build your own set →
Women's Base Layer Set
Need different sizes for the top and the bottoms? Build your own set →
Kids' Base Layer Set
Men's T-Shirt
Women's T-Shirt
Men's Long Sleeve
Same body measurements across 165, 190, 250 and 320gsm.
Women's Long Sleeve
Kids' Long Sleeve
Men's Long Johns
Women's Thermal Leggings
Kids' Thermal Leggings
Men's Half Zip
Women's Half Zip
Merino Wool Socks
Beanies, snoods and balaclavas
Still unsure which size to pick? Email info@merinotech.co.uk with your height, chest and waist and we will recommend a size. Free UK delivery over £49 and free returns within 30 days.
- Free shipping over $49.99
- 30-day easy returns
- Ships in 1–2 business days
Description
Women's Merino Wool Thermal Set
The Merino.tech Women’s Base Layer Set is engineered for performance and crafted for elegance. Merino wool’s fine fibres regulate temperature naturally — it warms when cold, cools when hot, and breathes continuously. Moisture evaporates instantly, keeping you dry even during peak exertion. Odour resistance means you can wear it multiple times between washes — ideal for travel and long expeditions.
The lightweight, flexible design follows your every move, offering comfort without restriction. It’s soft enough for sensitive skin and offers built-in UV and antistatic protection.
Ethically sourced and biodegradable, this set represents sustainable luxury for active women who value both comfort and conscience.
Care
Turn inside out. Machine wash cold on a gentle cycle with a wool-safe detergent. Do not bleach. Lay flat or hang to dry.
Shipping & returns
Free UK delivery on orders over £49. Ships in 1–2 business days. 30-day free returns on unworn items with tags.
Women's base layer set
Top and bottom, matched and ready
Long sleeve top and pants in the same weight and colour — the fastest way to a complete cold-weather base. Flatlock seams and a soft, non-itchy finish.
Size guide
Women's Set 250
Fit
The top and the bottoms come in the same size, with a close, next-to-skin fit. Need different sizes for the top and the bottoms? Build your own set.
How to measure
- Chest – around the fullest part of your chest, tape level under the arms.
- Waist – around your natural waistline, tape comfortably loose.
- Hips – around the fullest part of your hips and seat.
- Inside leg – from the top of your inner thigh to your ankle bone.
Measure over light clothing and keep the tape snug but not tight. Still unsure? Email info@merinotech.co.uk with your height, chest and waist and we will recommend a size. Unworn items can be returned free within 30 days.
THE FABRIC
Why merino wool
Merino wool moves sweat away from your skin as vapour and lets it evaporate from the fabric, so you stay dry and comfortable whether you are hiking, commuting or skiing.
Merino fibres naturally resist the bacteria that cause odour, so you can wear a base layer for several days, on the trail or while travelling, and it still smells fresh.
Wool can absorb up to 30% of its weight in moisture without feeling wet. In damp British weather it keeps insulating where cotton and polyester leave you cold.
Merino absorbs UV radiation: our lightweight layers offer UPF 25 and the midweight and heavyweight options UPF 50+, handy on long days in the hills.
Merino wool is naturally hard to ignite and self-extinguishes without melting onto the skin, unlike synthetic base layers.
Merino is a natural, renewable and biodegradable fibre. Sheep grow a new fleece every year, and a worn-out merino garment breaks down instead of shedding plastic microfibres.
FAQ
Women's merino thermal sets: FAQ
What is this 250gsm thermal base layer set best for?
It is a midweight 250gsm merino layer, best for skiing, hiking and cold UK winters. Compare every weight in our merino weight guide.
Which sizes are in stock?
Available to order now: , XS, S, M, L, XL, XXL. Our merino is true to size and designed to sit close to the skin; see the size guide for measurements.
Is this thermal base layer set warm enough for skiing?
Yes. 250gsm midweight merino under a ski jacket and trousers is the most popular choice for a ski holiday. Choose 320gsm if you feel the cold.
What is included in a women's merino base layer set?
A long sleeve thermal top and matching leggings in the same weight and colour, ready to wear together as a complete base layer.
Is a set better value than separate pieces?
Yes, the set price is lower than buying the top and leggings individually. To mix weights, colours or sizes, create your own combination in the set builder.
Which weight of set should I take skiing?
A 250gsm midweight set is the best all-round choice for a ski holiday. Go for 320gsm if you tend to feel the cold, and 165–200gsm for spring snow or active ski touring.
Can I wear the set as loungewear or pyjamas?
Yes. Merino regulates temperature, so the set is comfortable for sleeping in a cold house, camping or relaxing after a day outdoors.
What if my top and bottom sizes are different?
Pre-made sets use one size for both pieces. If you need different sizes, build your own set and choose each size separately. See the size guide.
I received my order and am happy with the purchase overall, however one of the base layer sets arrived with quite a bit of white hair on the item. Obviously this is not a “new” item and I believe you should have advised that this item was “used” or at least “returned”. I do not believe you should be charging the same for items that are obviously returned or previously used. I sent an email to customer service with attached pictures of the item so you can see that this is not a small amount of hair (seems to be dog or cat hair to me). I have not heard from you about this, yet.
This merino set was perfect! It fit well under all my other layers, kept me warm in the Icelandic cold, yet was still breathable. It definitely smells like wool when it’s washed and still wet at first (once it dries, the smell disappears), so be sure to wash separate or hand wash. However, I didn’t need to wash it during my trip since this set resisted odour pretty well, which I believe is a trait of merino wool. I’d definitely buy it again!
This merino set was perfect! It fit well under all my other layers, kept me warm in the Icelandic cold, yet was still breathable. It definitely smells like wool when it’s washed and still wet at first (once it dries, the smell disappears), so be sure to wash separate or hand wash. However, I didn’t need to wash it during my trip since this set resisted odour pretty well, which I believe is a trait of merino wool. I’d definitely buy it again!
Absolutely love!!
Absolutely love!!
I live in Vermont in a woodstove-heated house, and it’s been COLD this winter, I think wearing my new Merino Tech base layer actually does make a difference! Thank you!
I live in Vermont in a woodstove-heated house, and it’s been COLD this winter, I think wearing my new Merino Tech base layer actually does make a difference! Thank you!
loving them ...they are so soft and warm
loving them ...they are so soft and warm
Excellent! This set of merino wool underwear is wonderful and keeping me warm this winter. I bought a couple of sets because I am now wearing them everyday. So soft, not scratchy at all, and just the extra layer I need.
Excellent! This set of merino wool underwear is wonderful and keeping me warm this winter. I bought a couple of sets because I am now wearing them everyday. So soft, not scratchy at all, and just the extra layer I need.
Bought a set for cold weather hunting. Not only is the quality amazing, soft, and keeps you warm but I'm obsessed with the socks they come with for free! You can't find a set for this much anywhere else. At least not with this quality. There was a hiccup, my package did not contain my bottoms, so reach out to customer service and they sent me the bottoms within the week PLUS another pair of socks for the mess up. Loving everything about this company so far!
Bought a set for cold weather hunting. Not only is the quality amazing, soft, and keeps you warm but I'm obsessed with the socks they come with for free! You can't find a set for this much anywhere else. At least not with this quality. There was a hiccup, my package did not contain my bottoms, so reach out to customer service and they sent me the bottoms within the week PLUS another pair of socks for the mess up. Loving everything about this company so far!
Love the comfort and feel. Will be purchasing another set.
Love the comfort and feel. Will be purchasing another set.
Like the fit, the merino doesn't feel the same as the 250 black leggings
Like the fit, the merino doesn't feel the same as the 250 black leggings
I have bought Marino wool garments from these guys for a while and have always been satisfied with the quality and customer service. Great stuff for winters here in the Sierras!
I have bought Marino wool garments from these guys for a while and have always been satisfied with the quality and customer service. Great stuff for winters here in the Sierras!
Soft and warm
Soft and warm
Nice, warm, andvdoes not itch. Fits perfectly.
Nice, warm, andvdoes not itch. Fits perfectly.
I LOVE these base layers. I ordered two sets & I am so glad I did because when I tried them on, I did not want to take them off. I am 5'3'' and 150 lbs and a medium in the shirt and pants fit perfect. They are cozy & not itchy. The first set came very quickly but the second set got lost in transit. The owner was very quick to fix that issue and sent a new order which arrived quickly as well. I also got a free pair of wool socks which are great. I want to order a set in every color!
I LOVE these base layers. I ordered two sets & I am so glad I did because when I tried them on, I did not want to take them off. I am 5'3'' and 150 lbs and a medium in the shirt and pants fit perfect. They are cozy & not itchy. The first set came very quickly but the second set got lost in transit. The owner was very quick to fix that issue and sent a new order which arrived quickly as well. I also got a free pair of wool socks which are great. I want to order a set in every color!
I left a review but forgot the 5 starts! I love everything I bought, it’s so soft and comfortable, I have another order in my cart now!
I left a review but forgot the 5 starts! I love everything I bought, it’s so soft and comfortable, I have another order in my cart now!
They fit and feel as expected. I love them.
They fit and feel as expected. I love them.