What’s Inside Really Matters: A Guide to Underwear Fabrics

There’s a lot of talk about comfort in underwear, but not enough talk about what’s actually touching your skin. Fabric changes everything: how you move, how you sweat, whether you forget you're wearing it (which is kind of the dream).

This blog is a guide to common underwear materials; what they feel like, how they behave over time, and what we chose for our pilot product.

Fabric Comparison Table

Fabric	🧶 Feel	🌬️ Breathability	🧱Durability	🌱 Sustainability	💡 Good For
GOTS-Certified Cotton	Soft, familiar, stable	Excellent	High (with care)	High – certified, ethical, low-tox	Everyday wear, sensitive skin
Modal	Silky, smooth	Good	High	Moderate to high – lower-impact production	Lounge styles, soft-touch designs
Viscose	Smooth, light	Moderate	Medium	Moderate – depends on sourcing	Flowy silhouettes
Elastane (Spandex)	Stretchy, springy	Low (on its own)	Very high	Low – synthetic	Flexibility, shape retention
Nylon / Polyester	Sleek, synthetic	Low	High	Low – fossil-fuel-based	Sportswear

Cotton (especially certified): Reliable, breathable, and body-friendly for underwear fabric

Cotton works. It’s breathable, soft, and doesn’t trap moisture like synthetics. If your skin is sensitive, or if you’re just looking for underwear that feels nature to your skin, cotton is a solid bet.

We use GOTS-certified cotton in our boxers, that means the fabric is made according to global standards for environmental and social responsibility. It holds up well to daily wear and washing, and feels great against your skin, even during hot days or period days.

Photo by Mia Moessinger on Unsplash, cotton fabric

Modal: Super soft with a smooth touch, light and comfortable

Modal is made from beechwood pulp and is known for its silky feel and low environmental impact. It’s lightweight, drapey, and often used in sleepwear or ultra-soft pieces. It’s also great at keeping its shape after lots of washes.

While we’re starting with cotton, we’re also exploring modal blends for future styles. It can add an extra layer of softness and stretch, especially in styles that are close-fitting or designed for lounging.

Other fabrics you might run into

There are dozens of materials used in underwear today — here are a few common ones and how they behave:

• Viscose: A semi-synthetic made from wood pulp, often used in flowy styles. It can feel similar to modal but doesn’t always hold up as well.

• Lycra / Elastane / Spandex: These are names for stretchy fibers added to give your underwear bounce. Great in small amounts — not great as the main material.

• Nylon / Polyester: Lightweight and durable, but not super breathable. Often found in activewear underwear, but can trap heat and sweat if worn all day.

Gusset matters: Always 100% cotton

That little panel in the crotch? That’s the gusset, and it’s kind of the most important part of your underwear.

We use 100% cotton gussets for breathability and hygiene. Especially when you’re on your period, using pads, or just want that part of your underwear to stay dry and calm. When you purchase any brand, please make sure this part is 100% cotton.

The structure of boxer briefs

Quick summary: What we use (and why)

• Main fabric: >90% GOTS-certified cotton + <10% elastane (for softness + stretch)

• Gusset: 100% cotton

• Waistband: soft microfiber, no digging

  
  

We’re focused on fabrics that feel good on real skin, hold up over time :)

Got questions about fabrics or preferences we should know? DM us: we’re always learning too.