Short answer: Merino is wool from merino sheep, with fibres finer than ordinary sheep’s wool, so it feels softer and keeps you warm even when damp. On the other hand, it dries more slowly than synthetics, so it suits walks, cool days and longer spells outdoors better than sport with heavy sweating. Wash merino at a low temperature with wool detergent and dry it flat, away from the heating.
What is merino wool?
Merino is wool from merino sheep. Compared with coarser sheep’s wool, it has much finer fibres that bend against the skin instead of prickling it. The yarn is knitted into T-shirts, long johns, socks and hats, so merino clothing is mostly baselayers and accessories.
Wool is a natural fibre and polyester is a synthetic one, which is why the materials behave differently. Merino absorbs more moisture and keeps you warm when damp, but it dries more slowly. It is worn against bare skin as a baselayer, just like synthetic thermal underwear; how to choose between the different ranges is described in the guide How to choose a baselayer.
Why does merino keep you warm even when damp?
The crimped wool fibres trap air between them, and air insulates. The fibre can also hold more moisture than polyester, and the knit does not stop warming the moment it gets damp. Merino therefore keeps you warm even when it is partly damp with sweat, whereas cotton soaks up moisture at that point and turns cold.
There are limits. The fact that merino warms you when damp does not mean it is as warm as when dry. If you are properly soaked in sweat, moisture leaves wool more slowly than it leaves a synthetic, and you can chill quickly once you stop. After a strenuous climb, change into something dry, even if you are wearing merino.
Does merino itch?
It can, but much less than traditional wool. Wool itches because thick fibres press against the skin with their tips and irritate it. Merino fibres are thin and flexible, so most people can wear them directly against the body. More sensitive skin can react even to merino, for example on the neck, under the arms and anywhere the garment rubs against the skin.
- How much merino itches varies from garment to garment. It depends on the fibre thickness, the yarn and the way it is knitted, so one merino T-shirt may not bother you while another does.
- Start with a few hours. Try a new garment on a short walk, not straight away on an all-day hike.
- If even fine wool irritates you, choose synthetic thermal underwear with a smooth knit.
Merino or synthetic?
It depends on how much you sweat when you move and how often you will stop. Merino and synthetic (polyester) compared:
| Feature | Merino | Synthetic (polyester) |
|---|---|---|
| Moisture | absorbs more moisture and keeps you warm when damp | barely absorbs water and moves it away from the skin |
| Drying | slower, allow longer for drying | fast |
| Against the skin | soft and fine, may bother sensitive skin | smooth, stretchy knit |
| Suits | outings with breaks, cool days, walks and everyday wear | long sport with heavy sweating: the piste, cross-country skiing, fast running |
| Washing and drying | wool programme, low temperature, dry flat | as per the label, no fabric conditioner |
You do not have to choose just one. Merino alternates well with synthetics, depending on where you are heading.
When to choose merino and when synthetic?
Merino suits:
- hikes where you alternate walking with stops,
- wearing under a sweatshirt or jumper every day in the cold,
- longer spells outdoors without much movement, such as a stroll,
- when synthetics don’t suit your skin and you are looking for a softer material.
Synthetic is the safer choice:
- for all-day skiing, cross-country skiing and fast running with heavy sweating,
- when you need your clothes to dry overnight,
- when you don’t like wool against your skin even in a fine version.
Merino is only ever the first layer, with a sweatshirt or gilet and a jacket on top. How to put the layers together is shown in the guides What to wear skiing and What to wear cross-country skiing. When choosing the outer layer, the comparison Snowboard jacket or ski jacket will help, and for your hands there is the guide Ski gloves.
What merino clothing does NORDBLANC offer?
The range includes merino thermal underwear, socks and hats. An overview by the composition given on the products:
- Thermal underwear. Thermal tops and long johns for women and men, women’s shorts and men’s boxer shorts. The tops, long johns and shorts are 96–100% merino, and the boxer shorts are 94% merino and 6% elastane. The activities stated on the products are hiking, running and cycling. Collections: women’s merino thermal underwear and men’s merino thermal underwear.
- Socks. Merino compression socks contain 15–30% merino, supplemented by nylon and Lycra, and on some models acrylic. Collection: merino socks.
- Hats. Several hats are 50% merino and 50% acrylic, see winter hats.
Everything made of merino is together in the collection Merino. For all-day skiing and cross-country skiing, synthetics are more reliable because of the sweating.
How do you wash and dry merino?
Merino lasts a long time with gentle care; what harms it most is heat, friction and fabric conditioner. The label on the particular garment always takes priority, otherwise proceed as follows:
- Wash gently. Choose hand washing or a wool or delicates programme, usually at 30 °C. Turn the garment inside out, ideally put it in a wash bag, and wash it without zips and hook-and-loop fastenings, which snag the fibres.
- What to wash merino in. A liquid wool or delicates detergent is suitable. Leave out fabric conditioner, which clogs the fibres. Strong washing powders with bleach are not good for wool.
- Don’t wring or twist. Press the water out of the garment gently or press it into a towel. Spin it only briefly, and only if the label allows.
- Dry flat. Lay the garment out to shape on a dry towel or a drying rack, away from heating, direct sun and the tumble dryer. Merino takes longer to dry than synthetics. Wet merino hung up will stretch.
Further advice on caring for clothing is summarised on the Product care page.
Frequently asked questions
Why did my merino shrink in the wash, and can it be put right?
Wool shrinks (felts) when heat, moisture and friction combine, most often when washed at a high temperature, in a tumble dryer or when wrung out. Felting is irreversible: the fibres bond together and the garment becomes smaller and thicker. You can sometimes ease slight shrinkage by dampening the garment and gently stretching it into shape on a flat surface, but a badly shrunk garment usually cannot be saved. Next time wash according to the label, at a low temperature and without wringing.
Why does merino pill, and how do you remove the bobbles?
Bobbles form when fibres rub against each other, mainly under rucksack straps, under the arms and at the sides. This is normal with woollen products. Don’t pull them off, as that would damage the knit; remove them with a fabric shaver or carefully with scissors. There will be fewer if you wash the garment inside out in a bag and without zips and hook-and-loop fastenings.
Can you wear a merino T-shirt on its own, without other layers?
In warm weather or indoors yes, it is worn like an ordinary T-shirt. Outdoors in the cold, merino is only the first layer: a sweatshirt or gilet and a jacket go on top, and a thin T-shirt on its own is not enough in frost.
How does 100% merino differ from a blend with nylon or elastane?
Pure merino is made of a single fibre, so it behaves most like wool: it keeps you warm when damp, dries more slowly and is cared for like wool. Nylon adds strength, and elastane or Lycra adds stretch. At NORDBLANC the T-shirts, long johns and shorts are 96–100% merino, the boxer shorts 94% merino and 6% elastane, and the socks 15–30% merino with nylon and Lycra. You will find the merino content in the composition on the product page.
How can you dry merino faster before a trip or an outing?
After washing, squeeze the garment out without twisting, wrap it in a dry terry towel, and roll the towel and garment up carefully and press down so that the towel soaks up the water. Then lay the garment flat on a drying rack in a ventilated room. Heating, a hairdryer or a tumble dryer will not do it any good. Merino takes longer to dry than synthetics, so wash it in good time before you leave.