When winter sets in, comfort becomes non-negotiable. The right thermals for women should keep you warm without feeling bulky, itchy or restrictive. Yet many women still struggle with base layers that don’t quite work for real life, whether that’s commuting, working long days or layering under everyday outfits.

In this guide, we’re breaking down modal vs cotton thermals, focusing on what really matters for daily wear: breathability, softness and effortless layering. If you live in your thermals all winter, this one’s for you.

What Are Thermals and Why Do They Matter?

Thermals, also known as thermal underwear or base layers are designed to sit close to the skin, helping regulate body temperature while staying comfortable under clothing. The best thermals for women feel soft, stretch easily and layer seamlessly under knits, trousers and dresses.

Fabric choice plays a huge role in how thermals perform throughout the day.

Cotton Thermals: The Classic Option

Cotton thermals are familiar and widely worn. They’re naturally breathable, gentle on skin and easy to care for, making them a popular choice for light warmth.

Cotton thermal long sleeve tops and thermal tights work well for low-activity days or mild winter temperatures. However, cotton absorbs moisture rather than wicking it away, which can leave fabric feeling damp and heavy if you’re moving around or wearing layers all day.

Modal Thermals: Designed for Everyday Comfort

Modal is a plant-based fibre made from beechwood and is known for its exceptional softness. Modal thermals feel smooth and lightweight, offering warmth without bulk.

Compared to cotton, modal manages moisture better and stretches beautifully, making it ideal for long days and frequent layering. It feels more like a second skin than traditional thermal underwear.

Modal vs Cotton: What’s the Difference?

If you want thermals that disappear under clothing and still feel good at 5pm, modal is hard to beat.

Why Base Layers Matter for Daily Life

Good base layers aren’t just about warmth, they’re about making winter easier.

Whether you’re wearing:

• Thermal leggings under trousers, like our Viscose Legging
• Thermal long sleeve tops beneath knits, such as the Modal Long Sleeve Scoop Neck Top
• Lightweight thermal tanks layered under shirts or dresses, including the Modal Tank Top or Modal Lace Front Tank Top

…the right fabric keeps you warm without bulk or irritation.

For women juggling work, family, and life on the go, comfort isn’t a luxury, it’s essential.

Why We Love Modal in the baseLINE Collection

At The Foundation, we focus on fabrics that work for real life. The baseLINE Collection is made up of soft, breathable essentials designed to layer easily and feel comfortable all day.

Modal is central to The baseLINE thanks to its smooth, lightweight feel and natural stretch — ideal for everyday wear under work and weekend outfits alike.

Shop The baseLINE and build your winter foundation.

Which Is Better for You: Modal or Cotton?

Choose cotton thermals if:

• You prefer traditional, familiar fabrics
• Your days are low-activity or mostly indoors
• You’re after light warmth rather than all-day layering

Choose modal thermals if:

• You value superior softness against the skin
• You layer daily under work or casual outfits
• You want breathable comfort from morning to night

For most women, modal offers the best balance of warmth, breathability and everyday wearability, especially when thermals are part of your daily routine, not just an occasional extra layer.

Final Thoughts

Thermals should make winter dressing easier, not something you have to think about. The right base layer works quietly in the background keeping you warm, comfortable and confident without bulk, itchiness or constant adjusting.

If you’re ready to upgrade your winter essentials, The baseLINE Collection is designed to be worn on repeat, because feeling good starts with what’s closest to your skin.

FAQs

1. Are modal thermals warmer than cotton?
   Modal isn’t thicker than cotton, but it regulates temperature better, making it ideal for all-day comfort without overheating.
2. Do modal thermals stretch out over time?
   High-quality modal fibres hold their shape well, offering stretch without sagging or losing structure.
3. Are thermals only for outdoor wear?
   Not at all. Everyday thermals are perfect for work, errands, travel and layering under daily outfits.
4. Can modal thermals be worn under fitted clothing?
   Yes. Modal is lightweight and smooth, making it ideal for layering under knits, dresses and tailored pieces.
5. How do I choose the right thermals for everyday wear?
   Look for softness, breathability and ease of layering, thermals should support your day, not restrict it.