The best fabric for underwear depends on what you want from it: certified-organic cotton is absorbent and hard-wearing for everyday, TENCEL Modal drapes silky-light, and TENCEL Lyocell regulates moisture especially well when you move. In this guide we sort the key materials by use case, so you know which fabric fits when.
The key materials at a glance
Before we sort by use case, here are the fibres that really matter for underwear, and what they do.
Certified-organic cotton (kbA)
Cotton from controlled organic farming (kbA standard) is absorbent, hard-wearing and feels skin-neutral. It takes up moisture well and is easy to care for. Worldwide, less than 1 per cent of cotton is grown to the kbA standard; at erlich it is the main material in all our cotton basics. Read more in our guide to certified-organic cotton.
TENCEL Modal
Modal is a cellulose fibre made from beech wood. We use only TENCEL Modal from Lenzing, made from FSC- and PEFC-certified wood. Modal drapes silky-smooth, is light and soft, and keeps its handle over many washes. At erlich, Modal is used only in the women's range. Details in our guide to Modal.
TENCEL Lyocell
Lyocell comes from the same fibre family as Modal but is made in a closed-loop process. According to Lenzing, over 99 per cent of the solvent is recovered. Lyocell regulates moisture very well, dries quickly and stays in shape even when wet. That is why it suits active days, and we use it in both the women's range and the men's basics.
Lace and mesh
Our lace and mesh fabrics come from Italy or Turkey and consist of different polyamide and elastane blends depending on the collection. Sometimes recycled yarns are used, sometimes even partly biodegradable ones. Beyond stretch and light support, both also offer a fine, elegant look and the highest wearing comfort thanks to their softness on the skin. The exact composition is listed on each product page.
Which fabric for which use case?
Now the practical part: which material suits which situation?
For everyday
For everyday, certified-organic cotton and Modal/Lyocell are the obvious choice. Cotton scores on absorbency and durability, Modal on its silky handle and low weight. Both are breathable and easy to care for. If you are after basics to wear all the time, you will find them in Casual Cotton and Light Touch. Our lace pieces also work beautifully for everyday: the gussets are made with cotton or modal and the lace is so soft that it sits wonderfully on the skin, like a basic brief.
For movement and light sport
When you move, what matters most is how a material handles moisture. This is where Modal and Lyocell shine: they take up about as much moisture as cotton, but dry quickly and keep their shape even as you sweat. For light workouts and active days, also have a look at the activewear. One note for honesty: erlich makes everyday basics, not specialist ski or performance underwear for high-intensity sport.
For warm days
On warm days or at night, a material that takes up moisture and lets the skin breathe helps. Lyocell feels cool against the skin, cotton is especially breathable, and Modal is ultra-soft against the skin. Which direction you prefer comes down to feel: silky-light, familiar and hard-wearing, or soft and hugging.
For sensitive skin
If your skin reacts easily, smooth cellulose fibres like Modal and Lyocell, plus soft certified-organic cotton, are a good choice, combined with a supply chain tested to OEKO-TEX Standard 100. For what else matters, read our article on underwear for sensitive skin.
Comparison: fabric, properties, use case
| Material | Handle | Moisture | Care | Best use |
|---|---|---|---|---|
| Certified-organic cotton | soft, natural | absorbent | easy care, 30-40 °C | everyday |
| TENCEL Modal | silky, light | wicks well | gentle, 30 °C | everyday, warm days |
| TENCEL Lyocell | smooth, cool | regulates very well | gentle, 30 °C | movement, active days |
| Lace / mesh | fine, elastic | depends on blend | wash bag, 30 °C | look, stretch |
What sustainable fabric really means for underwear
With fabrics, sustainability is not a label you simply print on. In concrete terms, for us it means: certified-organic cotton instead of conventional cotton, TENCEL Modal and Lyocell from Lenzing made from certified wood, and in the case of Lyocell a closed-loop process with over 99 per cent solvent recovery according to Lenzing. On top of that, a supply chain tested to OEKO-TEX Standard 100.
What we deliberately leave out: unprovable claims or promises that sound good but that our products simply do not deliver. We prefer to name the concrete fibres and processes, so you can decide for yourself whether that meets your criteria.
Our recommendation by need
If you want hard-wearing basics for every day, the Casual Cotton Basics in certified-organic cotton are your starting point. For a silky-light feel, it is worth a look at the Modal underwear. And if you prefer something cool and moisture-regulating, the Light Touch Basics in Modal and Lyocell are the right pick.
Frequently Asked Questions
Which fabric is best for underwear?
It depends on the use. For everyday, certified-organic cotton and Modal are strong; for movement, Lyocell, because it regulates moisture especially well. All three are breathable and skin-friendly.
Which fabric is good for sport and movement?
TENCEL Lyocell, because it takes up moisture, dries quickly and stays in shape even when wet. That is ideal for light workouts. For high-intensity sport over hours, technical performance fibres are made for that, and we deliberately do not carry those.
What is the most sustainable fabric for underwear?
Factually, every fibre has pros and cons. Certified-organic cotton avoids synthetic chemical pesticides, and TENCEL Lyocell runs in a closed loop with over 99 per cent solvent recovery according to Lenzing. Whether that is the most sustainable for you depends on your criteria.
Is cotton or Modal better?
Both are good, just different. Cotton is more absorbent and hard-wearing, Modal is silkier and lighter. For absorbent everyday basics choose cotton, for a smooth, soft feel choose Modal.
Which fabric is good for sensitive skin?
Smooth cellulose fibres like Modal and Lyocell, plus soft certified-organic cotton, ideally with a supply chain tested to OEKO-TEX Standard 100. Also look out for flat seams and a low synthetic content.
How do I recognise good underwear fabric?
By the material details (quality natural or cellulose fibres), by a tested supply chain such as OEKO-TEX Standard 100, by clean workmanship, and by a fit that does not pinch or dig in.
Sources
- Lenzing TENCEL: closed-loop process, Modal and Lyocell from certified wood
- OEKO-TEX Standard 100: supply-chain testing criteria
