Modal is softer and more breathable than cotton, wicks moisture more efficiently, and resists shrinking better over time. Cotton is widely available and comfortable at first, but it holds moisture longer and tends to trap more heat, especially in warm conditions.
What modal actually is
Modal is a type of rayon made from beech wood pulp. The fibers are processed into a fine, smooth yarn that feels noticeably softer than standard cotton against skin. MicroModal takes that a step further, using even finer fibers for a fabric that drapes rather than bunches.
Lyocell, often sold under the TENCEL brand, comes from a similar wood-pulp origin but uses a closed-loop solvent process that recaptures most of the processing liquid. Both are considered more resource-efficient than conventional cotton farming.
How they compare on the things that matter
| Property | Modal / MicroModal | Cotton |
|---|---|---|
| Softness | Very high, stays soft after washing | Good initially, can stiffen over time |
| Moisture wicking | Faster, dries quicker | Absorbs well but holds moisture longer |
| Breathability | High, lighter fabric weight | Moderate, heavier weaves trap heat |
| Shrink resistance | Holds shape well | Prone to shrinking without care |
| Environmental sourcing | Wood pulp, lower water use | High water and pesticide use conventionally |
Peer-reviewed comparisons of eco-friendly apparel fibers confirm that modal-family fabrics generally outperform conventional cotton on sensory comfort and moisture management. [1]
Why temperature matters for underwear specifically
Research is clear that the area that needs to stay cooler than the rest of the body is sensitive to heat. [2] Cotton underwear, especially heavier cuts, holds moisture against skin and can raise local temperature during activity or warm weather. A lighter, faster-drying fabric keeps that zone drier and cooler by default. [3]
- Tight, heat-trapping underwear has been linked to lower markers of testicular function compared to looser, more breathable styles. [4]
- Fabric type matters alongside fit. A breathable material in a constrictive cut still limits airflow.
- Synthetics like nylon and polyester move moisture but can trap heat and carry dye or finish concerns that natural-fiber fabrics avoid. [5]
Oakman launches Fall 2026. Founding members get first access and founding pricing locked in. Reserve your spot.
Where Oakman fits
Oakman is built specifically for active men looking for scrotal cooling all day and want the option of a cold pack for cooling in the sauna or after heat exposure. The fabric is TENCEL MicroModal, naturally derived from wood pulp rather than plastic, blended with ROICA V550, a clean Japanese stretch fiber, rather than conventional spandex. The fit is athletic with a gusset, an extra panel that gives the testicles room and airflow. Dyes are bluesign approved, so what touches your skin is controlled all the way through the supply chain. That's a sourcing decision, not a certification claim, but it reflects the same thinking as the material choices.
Oakman launches Fall 2026. The Founding 100 get first access to the boxer briefs and the reusable cooling pack designed to go alongside them in a sauna routine.
Related reading
- Finnish Sauna vs. Infrared Sauna: What's the Real Difference?
- Sauna vs. Steam Room: Which Is Better for Your Health?
Related reading
Frequently asked questions
Is modal underwear better than cotton for everyday wear?
Modal stays softer longer, dries faster, and holds its shape better than cotton through repeated washing. For everyday wear, especially in warm conditions, those differences are noticeable from the first day.
Does underwear fabric affect scrotal temperature?
Fabric weight and moisture retention both influence local temperature. Heavier fabrics that hold moisture against skin tend to trap more heat in that area than lighter, faster-drying materials. [2]
Does underwear type affect sperm count or fertility?
Research has found that men who wear looser, more breathable underwear styles tend to have higher sperm concentration than those in tighter styles. [4] Fabric choice is one factor among many, and no single change guarantees an outcome.
How does modal compare to synthetic fabrics like polyester?
Synthetics move moisture quickly but can trap heat and raise concerns about dye and finish residues. Modal is naturally derived, breathes well, and tends to feel softer against skin than most synthetics. [5]
Does modal shrink in the wash?
Modal is significantly more shrink-resistant than cotton when washed on a normal cycle. Cold or warm water and a low-heat dry cycle keeps it in shape longest.
This article is for general educational purposes and is not medical advice. If you have specific concerns about fertility or your health, talk to a qualified clinician.
References
- Comparative Assessment of Sensory Comfort Properties Across Eco-Friendly Textile Materials for Apparel. 2025. Journal of Natural Fibers (Taylor & Francis). [Link]
- Durairajanayagam D, Agarwal A, Ong C. (2015). Causes, effects and molecular mechanisms of testicular heat stress. Reproductive BioMedicine Online. [Link]
- Comfort related woven fabric transmission properties made of cotton and nylon. 2021. Fashion and Textiles (Springer). [Link]
- Minguez-Alarcon L, et al.. (2018). Type of underwear worn and markers of testicular function among men attending a fertility center. Human Reproduction. [Link]
- Comfort related woven fabric transmission properties made of cotton and nylon. 2021. Fashion and Textiles (Springer). [Link]
