Home → Blog → Resources → Merino Wool vs. Synthetic Base Layers – Our Comparison Guide
If you’re looking for a new base layer, there’s a good chance you’re considering either a merino wool or synthetic design. They are the top two material choices for a reason, combining excellent performance, comfort, and practical design. However, both materials have their advantages and disadvantages. Which you select will be influenced by a diverse array of factors, ranging from odor control and longevity to sustainability concerns and budget. With this in mind, we created a comprehensive guide to the merino vs synthetic base layer debate, helping you make an informed decision about which is right for you.
First things first, what does a good base layer need to do? Base layers are a feature of most layering systems for outdoor and athletic wear because they are extremely effective at regulating body temperature, helping users stay warm by wicking sweat away from the skin and allowing it to evaporate. This impacts comfort significantly, as it prevents big temperature swings and ensures your clothing doesn’t soak up the moisture your body generates. Non-sweat-wicking clothing tends to do just that, becoming heavy in the process, and making you colder as your heart rate drops and you’re not exercising as intensively.
An effective base layer will keep you warm in cold environments while ensuring you stay dry when participating in outdoor activities or sports. For those who enjoy these activities in a more relaxed manner, this translates to greater comfort. For those who are more competitive, it means better comfort AND improved performance. Now you have a good understanding of the benefits of base layers, let’s solve the merino vs synthetic base layer debate and help you decide what’s best for you.
Merino wool is collected from Merino sheep, a special breed that originated in Spain but has since spread across the world. It is valued for its very fine wool. The fine fibers ensure merino fabrics are soft and non-scratchy, enhancing comfort. They also contribute to a material renowned for its breathability, excellent insulation, and natural odor resistance. These qualities make it an ideal choice for outdoor clothing and base layers, in particular.
Key benefits of merino base layers include:
Merino wool is incredibly effective at wicking moisture away from the skin and it continues to insulate the body and retain heat even when damp. As such, it fulfills the main criteria for an effective base layer – keeping you warm and comfortable while exercising.
At the same time, merino wool also helps regulate your body temperature in warmer conditions. It boasts excellent breathability, enabling air to circulate and cool as you hike, run, cycle, or climb. It is this unrivaled versatility that makes merino wool such a desirable material.
Merino wool also benefits from natural antibacterial properties. Bacteria and bacterial metabolic byproducts are one of the principal causes of bad smells in clothing, so this means merino base layers feature some built-in odor protection. Many athletes and outdoor enthusiasts love merino wool base layers because they can wear them multiple times without the fabric smelling. Even when they start to pong a bit, hanging the base layers out in a stiff breeze and air drying them for a while can help eliminate the odors.
Whereas traditional wool can be a bit scratchy and itchy on the skin, merino wool is soft and gentle. It doesn’t irritate and it feels great. As a result, it’s fantastic for clothing that’s usually in direct contact with the skin, like base layers.
Merino wool is biodegradable and renewable, making it a more sustainable choice than many other fabrics. Depending on the production methods used, it is typically less resource-intensive than other materials. For environmentally conscious consumers, this is a massive benefit and one of the main reasons merino wool is such a popular choice among users who spend considerable time in the great outdoors.
Merino isn’t perfect, though. No material is. So here are a few potential drawbacks to balance our analysis.
All the performance benefits associated with merino wool mean that it is often more expensive than synthetic alternatives. It is considered a premium material and production is more costly, resulting in a higher price tag for most merino base layers.
In some instances, merino wool is less durable than synthetic fabrics. However, this largely depends on the quality of the synthetic fabric in question. Compared to a premium synthetic, merino wool may be more vulnerable to abrasion and general wear and tear. Consequently, there’s a chance it won’t last quite as long. However, compared to a lower-quality synthetic, merino probably retains the upper hand.
Merino wool tends to dry slightly more slowly than synthetic materials, though it is considered a relatively fast-drying material compared to most textiles out there. This means it may not be your first choice if you expect very wet conditions on a multi-day adventure or expedition.
If you want to ensure your merino base layer lasts as long as possible, you must take care washing it. Put it on too hot or fast a wash, and you’re likely to damage the fabric and shorten its expected lifespan. Gentle washing at low temperatures or handwashing is best. Fortunately, the material’s anti-odor properties mean you need to wash it less frequently anyway. Add in an odor-control solution like Polygiene StayFresh™ and you can really reduce the amount you need to wash your base layer!
Having covered the natural fiber, let’s look at the other side of the synthetic vs merino wool base layer debate. Synthetic fibers are also common in the outdoor and athletic space and are a popular choice among those looking for an affordable option that still performs well. Synthetic materials are man-made through chemical processes in a lab environment. This enables manufacturers to adapt the fibers to specific performance requirements. It also means synthetic fibers encompasses a broad range of materials, many of which share performance characteristics but many of which also boast unique qualities.
Popular synthetic materials for base layers include (but are not limited to):
Key benefits of synthetic base layers include:
Synthetic wins the merino vs synthetic base layers debate when it comes to cost. They are generally cheaper to produce than merino wool designs, resulting in lower prices for users. If you are looking for an affordable, lightweight base layer that gets the job done but doesn’t necessarily hit premium performance levels, synthetic fabrics are a good way to go.
Synthetics are typically considered the most hardwearing and durable of all the performance fabrics. They are highly resistant to wear and tear, ensuring any base layers they are incorporated into benefit from a long lifespan and deliver excellent value for users.
Just like merino wool, synthetics are designed to facilitate sweat wicking and are very effective at moving moisture away from the skin and allowing it to evaporate. They will keep you dry and comfortable throughout high-energy activities.
Synthetics are usually more lightweight and less bulky than merino wool, making them an excellent option if you’re selecting a base layer for a multi-day trip and want something that packs down small. There’s not too much in it though, so this shouldn’t be too much of a concern unless you are going ultra, ultra-light.
Most synthetics hold up well to machine washing and are relatively low maintenance. As a result, they are a pretty practical option.
Synthetic materials have their fair share of drawbacks, too.
Synthetic fibers are much more likely to trap and retain unpleasant odors, even after a single wear. As they don’t feature built-in antibacterial qualities, they provide bacteria with the perfect growth environment and bad smells can quickly spread. One way of combatting this is looking for synthetic base layers that feature integrated Polygiene StayFreshprotection.
Consumers should be aware that synthetic materials are manufactured from petroleum-based substances. This makes them significantly less environmentally friendly than merino wool. Just as importantly, they shed and release microplastics into water and the surrounding environment.
While synthetic fibers wick away moisture and keep you warm, they are not especially breathable. This means they will not help to regulate body temperature as things warm up. In fact, they are likely to exacerbate the issue, trapping the heat your body generates and contributing to higher temperatures.
Both synthetic and merino base layers will perform well if you purchase a high-quality product. When selecting one or the other, it is a case of balancing the advantages and disadvantages and thinking about how you intend to use the base layer. We break it down into the following trade-offs.
Merino tends to result in a higher-quality base layer, but it is more expensive. It is also far more environmentally friendly than synthetic materials. However, if you want or need to go more affordable, synthetic remains a great option.
There is an argument that synthetics are better suited than merino wool base layers for short, high-intensity sports and activities like running, football, and cycling. In these use cases, the lightweight and durable designs are particularly useful. On longer activities, such as all-day or multi-day hikes, bikepacking trips, and cross-country skiing, merino wool is the better performer.
These two may sound pretty similar, but they are actually very different. Synthetics are easy to maintain – they are robust and you don’t have to worry too much about them in the washing machine. However, you will have to wash them more frequently as they will pick up smells quickly. On the other hand, merino wool is lower maintenance. The natural antibacterial properties mean you have to wash your base layer less frequently. However, when you do wash it, you need to do so carefully.
Both merino wool and synthetic base layers can be improved with advanced antibacterial textile additives like Polygiene StayFresh. Our industry-leading odor–control solution prevents the growth of odor-causing bacteria, promoting a fresher-for-longer smell and feel, and reducing the need for frequent washing. In turn, this extends your base layer’s lifespan by limiting its exposure to rough washing cycles that inevitably damage fabric and fibers.
While merino wool boasts natural antibacterial properties, these qualities aren’t as powerful and refined as in Polygiene StayFresh. Combining the two results in much more effective and comprehensive antibacterial protection. In synthetic materials, Polygiene StayFresh contributes the antibacterial protection users appreciate in merino, making up for some of synthetic layers’ deficiencies and adding even more value for customers.
By selecting Polygiene-treated base layers, users benefit from:
If you’re looking for Polygiene-treated base layers, check out the list at the bottom of our complete guide to base layers.
Polygiene technologies are ideally suited to the Sportswear and Outdoor sectors, and enhance product performance, deliver extra value for consumers, and help brands differentiate their clothing. Our solutions are used by some of the biggest brands in the industry, ranging from The North Face to ARC’TERYX. If you want to discuss how Polygiene technology can improve your product offering, don’t hesitate to talk to our knowledgeable team.
Learn more about Polygiene antibacterial technology for Sportswear and Outdoor clothing.
