If you've ever pulled on a pair of underwear on a 38°C Sydney afternoon and immediately regretted the fabric choice, this guide is for you. Two of the most popular natural fibres in Australian underwear — cotton and modal — both feel great, but they perform very differently in real conditions. Here's the honest comparison.

Quick answer

• Best for hot, sweaty days: Modal (better moisture-wicking, dries faster)
• Best for sensitive skin, everyday: Organic cotton (breathable, hypoallergenic, no dyes)
• Best for zero VPL under dresses: Modal (thinner, smoother)
• Best for durability wash-after-wash: Organic cotton
• Best for sustainability: Tie — both are natural, but GOTS-certified organic cotton has the lowest chemical impact

What is cotton underwear?

Cotton is the classic underwear fabric. It's soft, breathable, and hypoallergenic. But not all cotton is equal:

• Conventional cotton is grown with heavy pesticides and often blended with polyester or elastane. It traps heat and takes forever to dry.
• Organic cotton is grown without pesticides, softer wash-after-wash, and free from synthetic finishes.
• GOTS-certified organic cotton (like our Organic Cotton range) is the gold standard — certified from farm to finish, no chemical dyes, no microplastics.

What is modal underwear?

Modal is a semi-synthetic fibre made from beech tree cellulose — specifically Lenzing Modal, which is what we use. It's technically a rayon, but produced in a closed-loop process that recycles ~99% of its water and solvents. The result: a fabric that's smoother than cotton, drapes better, and moves moisture off the skin faster.

Head-to-head comparison

Breathability

Cotton wins for airflow — its short, hollow fibres let air pass through more freely. If you get warm easily but don't sweat heavily, cotton feels cooler.

Moisture-wicking

Modal wins for sweat — modal fibres actively pull moisture off the skin and release it into the air. Better for hot, humid Sydney or Brisbane conditions, or if you're active.

Softness

Modal is smoother on day one. But organic cotton gets softer with every wash — by wash 20 they feel comparable. Modal stays smooth longer; cotton develops a broken-in comfort.

Zero VPL (no visible panty line)

Modal wins — it's thinner and lies flatter under clothes. Our seamless modal g-strings are the best pick for tight dresses.

Sustainability

• Conventional cotton: heavy pesticide use, high water demand
• Organic cotton: much lower chemical load, but still water-intensive
• Lenzing Modal: sourced from sustainable beech forests, closed-loop production

Both are natural. GOTS-certified organic cotton is the safest bet if you have sensitive skin or care about chemical exposure. Modal is the better choice if you want lower water footprint.

Cost & longevity

Modal is typically 10-20% more expensive but holds its shape longer. Organic cotton lasts 100+ washes if cared for well. Both outlast synthetic blends.

Which should you buy?

If you live somewhere hot and humid, or you're active: reach for modal. Try our Cheeky G in Lenzing Modal.

If you have sensitive skin, want the most breathable option, or wear underwear all day: organic cotton. Start with our Organic Cotton collection.

If you can't decide: most Nat'v customers end up with a drawer that mixes both — cotton for everyday, modal for hot days and tight dresses.

The Nat'v approach

Every Nat'v Basics style comes in GOTS-certified organic cotton or Lenzing Modal — both are the highest-certified natural options in each category. Free shipping on AU orders over $99, plus our First Pair Guarantee: love your first pair or exchange within 15 days.

Shop Organic Cotton →  |  Shop Modal G-Strings →