Which Baselayer Should You Choose?
Trying to decide which baselayer suits your outdoor adventures best? Wondering how different fabrics handle moisture, warmth, and comfort? Let’s break down the key options to help you choose your ideal model.
In SHORT…
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What fabric types make up baselayers? Explore the unique benefits and drawbacks of merino wool, synthetic, and blended options.
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How does activity level influence your choice? Learn which baselayer works best for high-intensity versus moderate activities.
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What should you consider for different weather and skin sensitivity? Discover tips on insulation, breathability, and caring for sensitive skin during your adventures.
What is a Baselayer and Why You Need One?
Which baselayer should you choose for your outdoor adventures? If you’ve ever been on a walk and found yourself drenched in sweat, you know the importance of having the right gear. That sweat has to go somewhere, and with ‘regular’ clothing. It simply gets absorbed by the primitive fabrics and sits against your skin for the duration of your activity. This is where baselayers come in. Acting as the first line of defence, baselayers move moisture away from your skin and push it to the exterior of the garment to evaporate. It keeps you dry and comfortable and this is generally referred to as ‘wicking’. There are lots of different types of baselayers. What we’re going to talk about today are the three main types of fabrics and the pros and cons of each.
Which baselayer should you choose? Types of baselayer fabrics
When it comes to choosing a baselayer, there are three main types of fabrics to consider: synthetic, merino wool, and synthetic/merino wool blends.
Let’s dive in and explore what each of these fabrics can offer. By understanding the unique properties and benefits of them, you can make an informed decision about which baselayer should you choose for your outdoor activities.
Merino Wool baselayer
High quality merino wool dispels all the myths about wool being itchy. It’s incredibly comfortable next to skin thanks to the ultra-fine fibres and feels a lot like cotton, just nicer. The beauty of merino wool is that it has the natural ability to inhibit the build-up of odour. This means you can wear merino wool baselayers for days on end and they won’t smell. It also makes them brilliant for multi-day trekking and walking. It also does a fantastic job of regulating your temperature . The warmer you get, the more warmth is released to prevent overheating. Conversely, it will keep you warm during colder activities; much like it would on the merino sheep in Kiwi winters. They’re available in a range of different weights, thicknesses and designs, allowing you to choose the one that suits you best.
The downside to merino wool is that the natural fibres aren’t quite as durable as synthetic fibres. Also, due to its premium quality (most merino comes from New Zealand). Merino wool does come in at the higher end of the price bracket. However, it’s not a huge difference if you consider that you only need one layer for a multi-day trip rather than two or three. They can also last a decade or more with some care.
Choosing a Merino Wool Baselayer: Weighing the Pros and Cons
Pros:
- Non-itchy
- Odour-resistant
- Comfortable
- Moisture-wicking
- Temperature regulating
Cons:
- Long drying times
- Less durable than synthetic
- Expensive
Synthetic Fabrics Baselayers
Synthetic fabrics thrive during aerobic activities where you’re sweating heavily. The big advantages of synthetic fibres are that they wick sweat away exceptionally quickly and they dry far quicker than merino wool fibres. Like merino, they’re available in a wide range of weights to suit different seasons. They are super lightweight, loosely-fitting ones for spring/summer use and thick, snug-fitting ones for autumn/winter. Another big plus is that they’re easy to wash and dry quickly. Just bung in the wash at 30°C with some Grangers Active Wash and they’re good to go.
There are a few downsides, though. Synthetic fibres don’t have the same odour-controlling properties that merino wool has. This means that you’ll probably need two or three layers if you’re off for a multi-day trip (unless you’re happy offending your campmates). Some manufacturers are working odour-controlling technologies, like polygiene, into their garments, but even so, the nature of the fabric means that they can still get a bit pongy and will need washing more regularly. They’re also essentially made of plastic. Polyester is a form of plastic derived from petroleum. It isn’t as sustainable as a merino wool alternative which is simply sheered during warmer months when it’s no longer required. Many manufacturers are now using recycled polyester to limit the effects of this.
Pros:
- Comfortable
- Rapid moisture wicking
- Quick drying
- Easy to wash
- Cheaper then merino wool
- More durable than merino wool
Cons:
- Gets stinky quickly
- Requires more washing
- Essentially made of plastic
Synthetic & Merino Blend
Synthetic and merino wool blend garments are a combination of the two and share many benefits from both sides. The merino wool fibres are mixed with the synthetic fibres so you get the benefits of both. Durability, quick drying, high wicking properties of the synthetic fibres teamed with the comfort, softness, odour control and the consistent temperature regulation of merino wool. They still wash very easily in most cases.
They’re a little ‘jack of all trades but master of none’. If you prefer to move slower for longer, merino is unbeatable. If you’re moving quickly in the mountains and need absolute moisture-wicking, synthetic is the one to go for. Blended fabrics are good at both, but not as good as both. There are also more options available in either a pure merino wool garment or a pure synthetic garment. The fabric blend is also harder to make meaning the garments are usually more expensive than 100% synthetic or merino wool products.
Pros:
- Combines the benefit of both fabrics
- Good odour control
- Durable
- Soft
- Comfortable
Cons:
- More expensive than Merino and Synthetic garments
- Jack of all trades, master of none
- Fewer options available
What Do the Numbers Mean on Merino Wool for Baselayers? Are There Different Grades of Merino Wool?
When choosing a Merino wool baselayer, the numbers you see on the label refer to two main things: the micron count of the wool fibres and the fabric weight (gsm). These details help you understand how soft and comfortable the baselayer will feel against your skin and how it will perform during your activity.
Merino wool is graded based on the diameter of the fibres, or micron count:
Superfine Merino Wool (15-19 microns)
This is the softest and most comfortable grade of merino wool. A superfine merino wool baselayer will feel amazing against your skin, making it ideal for active use in cold to cool weather. It’s great for those who need a baselayer that won’t itch or irritate during long hikes, skiing, or other outdoor activities.
Fine Merino Wool (19-23 microns)
Still soft but a bit thicker and more durable, fine Merino is a good option for baselayers that need to handle more intense physical activity. It provides comfort without compromising performance, making it a great choice for those who need warmth and breathability.
Medium Merino Wool (23-28 microns)
This grade of wool is less common for baselayers but can be used in heavier, more durable options. A medium-grade merino wool baselayer will provide more warmth and durability but might not feel as soft against the skin, making it more suitable for extended wear in colder conditions.
In addition to the micron count, you might see fabric weights like 200gsm or 260gsm on merino wool baselayers. These numbers indicate the thickness of the fabric:
- 200gsm (grams per square meter): A lighter weight that is perfect for active wear in cooler weather, offering a balance of breathability and moisture-wicking.
- 260gsm: Heavier than 200gsm, this weight provides extra warmth, making it ideal for those who need more insulation in colder conditions.
So, when choosing a Merino wool baselayer, look at the micron count for softness and comfort and the fabric weight to ensure it meets your activity level and weather conditions.
Activity Type and Baselayer Selection
The type of outdoor activity you’re engaging in affects the kind of baselayer you should choose, as it influences factors like moisture management, temperature regulation, and comfort during movement.
High-Intensity Activities (Trail Running, Skiing, Climbing)
When you’re involved in high-intensity activities like trail running, skiing, or climbing, your body works hard, generating a lot of heat and likely sweating. For these activities, your baselayer needs to perform several essential functions:
- Moisture-Wicking: High-intensity activity produces sweat, and a baselayer that excels at moisture-wicking (pulling sweat away from the skin) is essential. Materials like synthetic fabrics (polyester, nylon) are typically good at this. They quickly move moisture to the surface, where it can evaporate, preventing the sensation of being damp and cold.
- Breathability: As you work hard, your body needs a baselayer that allows heat and moisture to escape without overheating. A breathable fabric lets air circulate, cooling you down while maintaining a barrier to regulate your body temperature.
- Quick-Drying: The quicker the baselayer dries, the less likely you’ll feel chilled or uncomfortable when sweat accumulates. Synthetic baselayers or lighter Merino wool options are often quicker to dry than heavier wool baselayers.
For example, polyester or nylon blends are great for high-intensity activities because they dry fast, wick away moisture, and keep you feeling fresh. Merino wool can also be used for these activities, but make sure it’s a lighter-weight option for the best performance.
Moderate to Low-Intensity Activities (Hiking, Camping)
The intensity may be lower for activities like hiking or camping, but comfort and warmth are still top priorities. You’ll likely be active but at a lower intensity or even sitting still during breaks, so your baselayer should help regulate body temperature in these conditions:
- Warmth: Since you might not generate as much heat as during high-intensity activities, the focus shifts toward warmth and insulation. Merino wool is excellent because it traps heat while still being breathable, even in colder conditions. It also works in the opposite direction by keeping you cool when it’s hot, offering a great balance of thermal regulation.
- Comfort: A softer, more comfortable baselayer is crucial when you’re on long hikes or setting up camp for an extended period. Merino wool is naturally soft and doesn’t cause itching like some synthetic options, making it ideal for these slower-paced activities.
- Moisture Management: Even though you might sweat less, moisture management is still important, especially in cooler temperatures where sweat can make you feel cold. A baselayer that draws moisture away from the skin, like merino or moisture-wicking synthetics, will ensure comfort, especially during breaks or when resting.
A heavier merino wool baselayer is perfect for moderate-intensity activities and colder weather. On the other hand, if you’re anticipating milder temperatures or more sedentary activity, synthetic baselayers may offer enough insulation and moisture management while being lighter.
Choosing the Right Baselayer for Different Weather Conditions
Cold Weather
When the temperature drops, your baselayer needs to do more than just wick moisture. It should also provide insulation to keep you warm while allowing excess moisture to escape to prevent you from getting cold once you stop moving.
- Merino Wool: Merino wool is a standout choice for cold weather because it’s naturally insulating, even when wet. Its fine fibres trap heat while still allowing moisture to escape. Merino wool also offers breathability, which is important in maintaining a comfortable body temperature during colder activities like snowshoeing or winter hiking.
- Heavier Synthetics: If you’re doing less active winter sports like snowboarding or skiing, where you’re stationary for periods, you might want a thicker, more insulated synthetic baselayer (such as Primaloft blends or polyester) to provide warmth without the weight. These options keep you warm and dry, even if you’re not moving quickly.
Hot Weather
In hot weather, your baselayer’s primary job is to help with temperature regulation and moisture management while keeping you cool.
- Breathability and Lightweight Fabrics: For warmer weather activities like summer hiking or trail running, choose baselayers made from lightweight, breathable fabrics. Polyester and merino wool are both fantastic choices for this. Polyester quickly wicks moisture away and is lightweight, making it a great option for breathability and quick drying.
- Merino Wool for Heat Regulation: It may seem counterintuitive, but Merino can also excel in hot conditions. It has natural moisture-wicking properties and is breathable, helping to regulate body temperature by drawing moisture away from the skin. Merino wool also has natural odour-resistant properties, which is a bonus when sweating more.
- UV Protection: In hot conditions, UV protection becomes an important factor. Many baselayers, especially those made from merino wool or synthetic fabrics, offer UPF (Ultraviolet Protection Factor) to shield you from harmful UV rays during long hours under the sun. This added feature can be a game-changer during summer hiking, running, or biking.
In these conditions, you’ll want a lightweight merino wool or synthetic baselayer with ample airflow and ventilation. These fabrics keep you dry, cool, and comfortable, ensuring you don’t overheat during active outdoor pursuits like hiking, biking, or running.
Environmental Impact of Baselayers
As outdoor enthusiasts and eco-conscious consumers become more aware of their environmental footprint. Sustainability plays an increasingly important role in the decision-making process when selecting baselayers. Here’s a deeper look into what makes baselayers sustainable and why they matter:
Eco-Conscious Materials
Regarding baselayers, your chosen material can make a difference in environmental impact. Many outdoor brands are shifting towards eco-conscious fabrics and sourcing methods, which helps reduce waste, energy consumption, and reliance on virgin resources. Here are some key sustainable materials used in baselayers:
- Recycled Polyester: Traditional polyester is made from petroleum-based products, contributing to high levels of resource consumption and carbon emissions. On the other hand, recycled polyester is made from post-consumer plastic waste, such as plastic bottles, discarded fabrics, or other plastic products. This process significantly reduces environmental impact, as it prevents plastic waste from ending up in landfills and requires less energy to produce than virgin polyester. Many brands now offer baselayers made from recycled polyester, making it a great option for reducing carbon footprint.
- Recycled Nylon: Like recycled polyester, recycled nylon is made from post-consumer waste, including discarded fabrics and plastic materials. It’s durable, lightweight, and ideal for activewear like baselayers. By choosing recycled nylon, you’re helping to divert waste from landfills and supporting the reduction of environmental harm caused by manufacturing new materials.
- Responsibly Sourced Merino Wool: Merino wool is naturally biodegradable and has many sustainable properties. However, the environmental impact of wool production depends mainly on the farming practices. Responsible wool sourcing ensures that sheep are raised in a humane, environmentally friendly manner. Certifications like ZQ Merino or Responsible Wool Standard (RWS) ensure that the wool is sourced from farms prioritising animal welfare, sustainable grazing practices, and reduced environmental impact. This means less land degradation, reduced pesticide use, and better overall farming practices that support both the environment and the animals.
FAQ
No, a baselayer and thermal are not the same. A baselayer is the first layer worn next to the skin, designed to wick moisture and regulate body temperature. Thermals are typically baselayers made from insulating fabrics like merino wool or synthetic materials, but they are specifically designed to provide warmth in colder conditions.
To be precise, a baselayer helps protect you from getting cold. It happens thanks to trapping heat close to your body and preventing heat loss. Merino wool baselayers are particularly effective because they naturally regulate your body temperature, keeping you comfortable by allowing heat to stay in when it’s cold and letting excess heat escape when it’s warm. However, you may need a thicker or more insulating baselayer in extremely cold conditions to provide additional protection.
Baselayers should be snug but not tight. A snug fit ensures the baselayer has maximum contact with your skin, allowing it to wick moisture efficiently and prevent heat loss. This close contact helps the baselayer perform well in moisture management and temperature regulation. It should feel comfortable and flexible, allowing for movement without being restrictive. If the baselayer is too loose, it may not perform as effectively, as it won’t be able to manage moisture and heat.
The difference lies in the weight.
200gsm merino wool is lighter, making it great for active use in cooler weather or as a base layer during high-intensity activities.
250gsm merino wool is thicker and provides more insulation, ideal for colder conditions or slower-paced activities where you need more warmth.
Yes, 100% merino wool can be a great choice for a baselayer, especially for moderate to low-intensity activities. It offers natural moisture-wicking, temperature regulation, and odour resistance, making it perfect for extended wear in cold and mild weather. However, while merino wool is effective at wicking moisture, it is not as quick-drying or efficient at moisture management as synthetic fabrics (like polyester) during high-intensity activities where you sweat a lot. Merino is best for situations where temperature regulation and comfort are key. Synthetic fabrics on the other hand may outperform Merino in terms of moisture control for activities with intense perspiration.
Yes, you can wear a bra under a baselayer if desired for additional support. Some baselayers are designed with built-in support, especially for women. If you need more, a sports bra or regular bra works fine under your baselayer. When choosing a bra to wear under your baselayer, look for breathable, moisture-wicking, and quick-drying fabrics to complement your baselayer’s performance.
If you have sensitive skin, merino wool is a great choice because it’s soft, hypoallergenic, and naturally moisture-wicking. It’s much less likely to irritate the skin compared to synthetic fabrics. Look for merino baselayers that are superfine or have a smooth texture to minimise any discomfort.
Absolutely! A baselayer can be worn during workouts, especially during intense exercise. Synthetic baselayers are great for gym sessions as they wick away moisture quickly and dry faster. For cooler environments, a merino wool baselayer can help regulate your temperature, keeping you comfortable working out in colder indoor spaces or during outdoor runs.
The number of baselayers you need depends on the length of your trip, activity level, and weather conditions. For short outings, one baselayer may suffice, but for longer trips or multi-day adventures, it’s advisable to have at least two. Having two baselayers allows you to rotate them while washing one. You may also want to choose different weights for varying conditions, such as a lightweight baselayer for warmer weather and a thicker one for colder conditions.
Yes, you can wear a baselayer on its own, especially in milder weather conditions or for less intense activities. A baselayer can provide enough comfort and moisture management for many outdoor activities. But for colder temperatures, you will likely need to layer it with other garments like midlayers or outer layers for added insulation and protection from the elements.
Which baselayer should you choose? Summary
Choosing the right baselayer can make all the difference in your outdoor adventures. In the blog “Which Baselayer Should You Choose?”, we explored the three main types of baselayer fabrics and their pros and cons.
We stock a massive range of short sleeve, long sleeve, synthetic, merino, blended, zipped and non-zipped baselayers from various brands — you can have a peruse here. If you’re still confused, contact our helpful customer service team.
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