What is modal fabric?
Modal is a semi-synthetic fiber made from beech wood pulp. It is a type of rayon — chemically processed plant material that has been converted into fiber. Modal is softer and more shrink-resistant than standard viscose rayon, which is why it appears frequently in underwear, activewear, and bedding. Despite the plant origin, modal is not a natural fiber.
How modal is made
Beech wood chips are pulped and dissolved in sodium hydroxide. The resulting cellulose solution is pushed through spinnerets — small holes that form fine filaments — and then hardened in a sulfuric acid bath. The fiber is washed and dried before being spun into yarn. The production steps are similar to viscose but use different chemical concentrations and beech wood specifically, producing a finer, softer result.
| Fiber | Source | Classification | Chemical process |
|---|---|---|---|
| Cotton | Cotton plant seed pod | Natural | None — picked and spun |
| Linen | Flax plant stalk | Natural | None — retted and spun |
| Wool | Sheep fleece | Natural | None — shorn and spun |
| Viscose / Rayon | Wood pulp (various) | Semi-synthetic | NaOH + carbon disulfide + acid bath |
| Modal | Beech wood pulp | Semi-synthetic | NaOH + modified acid bath |
| Lyocell / Tencel | Wood pulp | Semi-synthetic | Closed-loop NMMO solvent (cleaner) |
| Polyester | Petroleum | Synthetic | Full petroleum-to-fiber synthesis |
What is modal fabric?
Modal fabric is a semi-synthetic fiber made from beech wood pulp that has been chemically processed into fiber. It is a type of rayon — specifically a higher-quality version developed to be softer and more shrink-resistant than standard viscose. Despite starting from a natural source, modal is not a natural fiber. The chemical conversion process transforms the wood pulp at a molecular level into something that does not exist in nature.
Is modal a natural fiber?
No. Modal is a semi-synthetic fiber. The beech wood it comes from is natural and renewable, but the fiber itself is manufactured through a chemical process. The wood pulp is dissolved in sodium hydroxide, extruded through spinnerets, and hardened in an acid bath. What comes out is regenerated cellulose fiber — a manufactured product, not a naturally occurring one. Natural fibers such as cotton, linen, wool, and silk are spun or woven from fiber in its natural state, with no chemical conversion.
Is modal the same as rayon?
Modal is a type of rayon. Rayon is the broader category for regenerated cellulose fibers — it includes viscose, modal, and lyocell. Modal was developed specifically from beech wood pulp using a modified process that produces a softer, stronger fiber than standard viscose rayon. Viscose, modal, and lyocell all start from plant material and are converted into fiber through chemical processing, making all three semi-synthetic.
Modal vs cotton: what is the difference?
Cotton is a natural fiber grown from a plant and spun with no chemical conversion. Modal is a semi-synthetic fiber manufactured from chemically processed wood pulp. Modal is often marketed as softer and more moisture-wicking than cotton, and it resists pilling better than most cotton. However, it is not a natural fiber, does not biodegrade at the same rate as cotton, and its production involves more chemicals than cotton farming. For people looking specifically for natural fiber clothing, cotton and linen are the more relevant alternatives.
Is modal the same as viscose?
Modal and viscose are both types of rayon and share the same basic production method. The main differences are in the wood source and process conditions. Modal uses beech wood and a modified wet spinning process that produces a finer, softer fiber that retains more strength when wet. Viscose can use various wood sources and results in a weaker, less soft fiber. Modal is generally considered a step up from viscose in quality, but both are semi-synthetic.
Is modal fabric sustainable?
Beech trees require less water and no fertilizer compared to cotton, which is a genuine advantage at the raw material stage. However, modal production still uses sodium hydroxide and sulfuric acid, and the chemicals in conventional production can be harmful if not managed properly. Lenzing's branded TENCEL Modal uses tighter process controls and partial solvent recovery, making it cleaner than conventional modal. Overall, modal sits between conventional viscose (worse) and lyocell (better) in environmental impact.
Does modal shrink?
Modal is more resistant to shrinkage than standard viscose but can still shrink if washed in hot water or put in a hot dryer. Wash modal in cold or warm water on a gentle cycle and tumble dry on low or hang to dry. Modal maintains its shape better than most rayon types under normal laundry conditions, but repeated hot washing will cause gradual shrinkage and loss of softness over time.
Is modal breathable?
Modal is moderately breathable. It absorbs moisture well and feels lighter and cooler than most synthetics. It is not as breathable as linen or cotton, but it is significantly more comfortable than polyester in warm conditions. Modal is often used in underwear and activewear specifically because it wicks moisture and dries relatively quickly while staying soft against skin.
Why is modal not in The Plain Thread directory?
The Plain Thread lists brands that use natural fibers — fibers that occur in nature without chemical conversion. Modal, viscose, rayon, and bamboo fabric all require chemical processing that transforms the raw plant material into something new. They are semi-synthetic, not natural. We do list lyocell (Tencel) in limited cases given its closed-loop production process, but it is still not a natural fiber. If you're looking for clothing made from natural fibers, cotton, linen, wool, hemp, and silk are the categories to explore.
Every brand in The Plain Thread directory uses natural fibers: cotton, wool, linen, hemp, silk, alpaca, and cashmere. No modal, no viscose, no polyester.
Browse natural fiber brands