The Short Answer
Cotton is a natural plant fiber — breathable, absorbent, hypoallergenic, but it wrinkles, holds moisture, and lacks stretch. Microfiber is a synthetic (nylon or polyester) woven from ultra-fine filaments — smooth, quick-drying, stretchy, and invisible under clothing, but it traps heat and can irritate sensitive skin.
Fabric Properties Side by Side
| Property | Cotton | Microfiber |
|---|---|---|
| Fiber origin | Natural (plant) | Synthetic (nylon/polyester) |
| Surface | Matte, slightly fuzzy | Smooth, subtle silky sheen |
| Breathability | Excellent — air passes through easily | Moderate — less airflow |
| Moisture | Absorbs and holds moisture | Wicks moisture, dries faster |
| Stretch | Low (unless knitted jersey) | Moderate, good recovery |
| Transparency | Opaque | Opaque |
| VPL risk | Higher — thicker fabric shows lines | Lower — thin, smooth edges |
| Durability | Fades, shrinks over time | Holds shape and color well |
| Skin sensitivity | Hypoallergenic | Can irritate some skin types |
How to Tell Them Apart: The Visual Test
Touch the surface and look closely.
- Cotton: the surface has a matte, slightly textured or fuzzy quality. Individual fibers may poke up from the surface (pilling on older garments). There's no sheen at all.
- Microfiber: the surface is noticeably smoother, with a faint silky sheen. It feels slippery compared to cotton. The weave is so tight that individual fibers are invisible — the surface looks almost featureless.
The water test is definitive: drop water on each. Cotton absorbs it instantly and darkens. Microfiber beads the water briefly before absorbing, and the wet spot dries much faster.
Common in Lingerie
Cotton dominates everyday panties and basic bralettes. It's the default recommendation for sensitive skin and daily wear. Cotton with a lace waistband is the classic "comfortable but feminine" style. Most panty gussets (the reinforced crotch panel) are cotton regardless of what the outer fabric is.
Microfiber dominates T-shirt bras, seamless underwear, and anything designed to be invisible under clothing. It's the fabric of choice when you need a smooth silhouette — molded cup bras, laser-cut panties, and shapewear all rely on microfiber's sleek surface.
The practical rule: cotton for comfort at home, microfiber for invisibility under clothes.