Viscose goes by a few names. On one tag it's viscose, on another rayon, on a third it hides inside the word "modal." It shows up in flowy dresses and soft linings and that slinky blouse that feels almost like silk for a fraction of the cost. And because it comes from a tree, it gets sold to you as the natural, plant-based choice. That story is half true, which is the most useful kind of thing to understand, because it's the half that's missing that tells you what you're actually buying.
Viscose is made from wood pulp. Technically it's cellulose, the same backbone as cotton, drawn from a plant. But cotton is spun more or less as it grows. Viscose has to be dissolved into a thick liquid first, and the process that does the dissolving is the part the marketing skips.
The chemistry between the tree and the dress
To turn solid wood into a fluid you can spin, viscose is treated with caustic soda and a solvent called carbon disulfide. Carbon disulfide is not a gentle chemical. The Changing Markets Foundation has documented how, in the factories where viscose is made cheaply, it has harmed the workers who handle it and the rivers that take the runoff. None of that ends up on the finished tag.
So while viscose technically starts as a plant, by the time it reaches your closet it has been through a chemical bath that cotton never sees. The fiber that lands on your skin is cellulose again, the harshest chemistry is spent during manufacturing rather than worn home, which is the honest nuance most "viscose is toxic" takes leave out. But the manufacturing matters. A fabric that pollutes a river and sickens a factory worker on the way to being soft is not the clean, plant-based thing the front of the tag implies.
Where the wood comes from
There's a second story behind viscose, and it's about forests. Because viscose is made from wood pulp, demand for it pulls on trees, and watchdog groups like Canopy have shown that some of that pulp has come from ancient and endangered forests rather than tidy, replanted plantations. A fabric marketed as the earth-friendly option can quietly carry a piece of an old-growth forest in it. The better mills now source from certified, responsibly managed wood, but the tag almost never tells you which kind you're holding.
On your skin
The honest part: viscose feels lovely. It's soft, cool to the touch, and drapes closer to silk than cotton ever will. When dry, it breathes reasonably well, which is why it shows up in so many summer dresses. The catches are practical. Viscose is weak when wet, so it pills, wrinkles, and loses its shape faster than cotton, and it often can't take a normal wash without shrinking. To firm it up and make it behave, manufacturers add finishing chemicals, and those finishes are extra chemistry sitting against your skin.
Cotton is the plainer sibling. It's less silky and less fluid, but it's tougher, more absorbent, easier to wash, and far simpler in what it's made of. For everyday pieces worn close to the body, simple is usually the safer bet.
"Plant-based" tells you where a fabric began, not what was done to it on the way to your closet.
The "bamboo" sleight of hand
One label trick is worth knowing by name. A lot of clothing sold as soft, eco-friendly "bamboo" is really just viscose made from bamboo pulp, dissolved with the same harsh chemistry as any other viscose. The plant changed; the process didn't. In the United States, the Federal Trade Commission has gone after brands for exactly this, ruling that fabric made this way has to be labeled rayon, not bamboo. When you see "bamboo" on a soft, drapey fabric, read it as viscose with better marketing.
Not all wood-pulp fabrics are equal
This is the nuance worth keeping, because it changes what you should buy. Viscose has a cleaner cousin: lyocell, sold most often as Tencel. It's made from the same kind of wood pulp, but in a closed-loop process that captures and reuses a far less toxic solvent instead of carbon disulfide. Same soft drape, far less of the dirty chemistry and river pollution. Modal sits in the middle, a stronger, often more responsibly made cousin of viscose, especially when it carries a brand name like Lenzing that ties it to a known supply chain.
So the family tree matters more than the fact that all of them come from trees. If you love the way viscose falls, lyocell and Tencel give you most of that feeling with a much cleaner story behind it. The word on the tag is doing real work here, and it pays to read which cousin you're getting.
Care and longevity
Viscose asks for patience. It's prone to shrinking and watermarking, often wants hand-washing or dry cleaning, and weakens when it's wet, so a beloved viscose dress can wear out faster than a cotton one bought the same day. Cotton is more forgiving in the wash and tends to age into softness rather than falling apart. If you want the silky drape but not the upkeep, lyocell is again the friendlier choice: it holds up better to washing than plain viscose.
What it means for your closet
For everyday pieces against the skin, cotton, and organic cotton when you can, stays the safer default: a simpler fiber with a shorter story and an easier life in the laundry. When you want that liquid drape viscose is known for, look for lyocell or Tencel, or a named modal, rather than plain viscose, rayon, or "bamboo." The fabric will feel nearly the same and carry far less behind it.
Telling them apart is the hard part, because the tag rarely explains the difference between one wood-pulp fabric and another. Toxome reads the composition for you and scores what the fabric actually is, so "plant-based" stops being the end of the conversation.