What Is Rayon? A Textile Engineer Breaks It Down

I hear you… What is rayon? Are viscose and rayon the same thing? Is rayon sustainable? Is rayon synthetic? Does rayon biodegrade? Which fabric is better rayon or viscose? What about rayon vs viscose vs polyester? Here is everything you could possibly want to know about rayon to decide for yourself it's a fiber you want in your closet.

It feels like everyday conscious women are being told a new fiber is destroying the planet, and they need to overhaul their closets. To me, this constant game of cat and mouse, buy this, no it’s bad, now buy this, seems crazy. I think the best approach is for women to make their own decisions on what they feel is sustainable. We don’t need to be told by companies what to do, give us the info so we can make the decision ourselves.

But, before we get started

Let's start with the basics.

Before we get into any of this, first we need to define rayon. Rayon meaning, rayon fibers are textile fibers made from regenerated cellulose by extrusion through minute holes.

What does that even mean? We will break it all down in this article.

What Is Rayon?

Rayon is an umbrella term for semi-synthetic fibers made from cellulose. Viscose, Modal, Lyocell, and Tencel are all different types of rayons. 

Viscose vs Rayon

Let's start with the basics.

The term viscose refers to how the rayon is made. (more on that below)

Viscose, aka "viscose rayon" is a type of rayon, and is actually the most common type of rayon. Kind of like how all squares are rectangles, but not all rectangles are squares - the two are not interchangeable. So viscose actually falls under the umbrella of rayon, kind of like how Cap'n Crunch is a type of cereal, an apple is a type of fruit… you get the idea.

What Is Rayon Made From?

Rayon is made from cellulose derived from plants like trees, bamboo, and even cotton waste.

Do you know that new groundbreaking orange fiber fabric that Ferragamo is using? Well, technically, it is just rayon. Instead of the cellulose in the process coming from trees, it comes from oranges.

And, How Exactly Is Rayon Made?

Rayon is made by mechanically pulping plant cellulose and then chemically liquifying the pulp with toxic chemicals. The pulp is then extruded to create fibers which are spun into yarns, and then knit or woven into a fabric.

Synthetic Fibers Are Not Spun, They Are Extruded

Fiber is extruded through a spinneret during the rayon production process

In rayon production, viscose rayon fibres are extruded into a chemical bath, and then, yarns can be spun.

What Is Extrusion?

Wood pulp mixed with chemicals to create a viscous is pushed through a spinneret. A spinneret looks like a mini spaghetti strainer, it can have one hole or lots, and the holes can be in different shapes to give the fiber they are creating different characteristics. For example, a round fiber will be shiny, and one shaped like a star is dull, and probably has decent heat retention. Once the viscous is pushed through the spinneret, it enters a chemical bath where it is extruded into a fiber. After the fiber has been extruded, yarns can be spun.

If you really want to get into how rayon is made and learn more about all the different methods like wet modulus production, check out our TEXTILES 101 course on synthetic fibers.

Is Rayon Synthetic?

To answer that we need to answer the question, what is rayon made of?

Speaking of synthetic fibers... Yes, rayon is any type of synthetic or semi-synthetic fiber (depending on who you ask) that is made from cellulose. Because rayon fibers are made from tree and plant pulp, companies now market rayon as natural fibers. But, rayon natural fiber is just more greenwashing. These fibers are heavily processed with extremely toxic chemicals.

Again, for the people in the back. Is rayon a natural fiber? No! But, it is made of natural things.

What Is Rayon Fabric Used For And Why Was It Developed

What is rayon fabric used for, and why was it developed? Rayon was developed to replace silk and is also known as artificial silk. FYI, if you are interested in the history of rayon, this article is worth checking out. The fiber in many ways feels like silk, but because it is made of plant cellulose, on a molecular level it behaves much like cotton.

What Is Rayon Used For?

Rayon fabrics are generally used to give clothes that soft, flowy look. When I think of rayon clothing, I think of the clothes that flutter as your walk, creating an ethereal goddess vibe. It is the modal man between cotton and silk.

What is rayon used in? Well, everything. Rayon fabric is currently the most popular fabric in women's fashions.

Rayon vs Cotton

Because on a science level rayon material is so similar to cotton, I often am asked - is rayon cotton? The answer is no. Not at all. Not even close.

I can see where some might get confused. It is true that during the dye, print, and finish process cotton and rayon behave similarly, so they use the same chemical dyes and processes. Whereas something like polyester needs a totally different set of chemical processing.

Breaking Down The Many Types Of Rayon

There are different types of rayon, as mentioned earlier. While marketers want to categorize rayons by what they are made of and the chemicals used, the textile industry breaks rayons down by the process they are made in.

Today rayon manufacturing processes have three fibers generations - viscose, modal, lyocell.

Viscose Rayon

Viscose rayon is the first generation of rayon processing. And, is the dirtiest. The problem with viscose rayon processing is that back when the process was created, fashion was not thinking about what to do with the chemicals after using them. Because of this, the toxic by-products from rayon viscose processing in developing countries tend to be disposed of illegally, being dumped into local waterways.

If you are curious about the destruction that carbon disulfide and rayon creates and why its production is no longer allowed in the United States check out this super interesting article from The Atlantic.

Types Of Viscose Rayon

There are lots of different types of viscose rayon, and they all use different chemicals and have different impacts on the environment. Viscose rayon can be thought of as just regular rayon and is the most popular rayon on the market.

There are other examples of rayon. Another popular rayon is acetate rayon. Taffeta prom dresses in the late 80’s and early 90’s were generally made out of this type of rayon. Did you know that acetate fabric can be completely dissolved at home using nail polish remover?! There is also cuprammonium rayon (made with copper and ammonia), Each type has its own set of pros and cons.

With About All Of Those Chemicals, Is Viscose Rayon Even Safe To Wear?

Yes and no. Yes, the sulfuric acid is most likely gone. But the rayon undergoes many more chemical-intensive steps after the extrusion process and is not necessarily safe for the consumer.

After extrusion, fibers aren’t simply just washed and ready to go. They are spun into yarns using either pot, spool, or continuous spinning methods. Then they are bleached, rinsed, dried, and wound on spools to be used in fabric manufacturing. The fibers also need to be dyed using fiber reactive dyes or in the case of acetate rayon, disperse dyes. And finally, once a fabric is either knit or woven from the yarns, often times formaldehyde or other chemicals are used during the fabric finishing process. The end result is a chemical cocktail on your rayon clothes.

So, Is Viscose Sustainable? Maybe I Should Stop Buying Viscose Fabrics?

The thing is, a lot of rayon factories are starting to do a lot to clean up their acts, like sourcing wood from sustainable suppliers. They aren’t perfect yet. It is impossible to overhaul the supply chain systems overnight, but steps are in place towards a greener future. 

So, while traditionally it hasn't been the greenest fiber, viscose is becoming more environmentally friendly

Modal, Lyocell, + Tencel

What Is Modal Fabric? And, Is It A More Eco Option?

Modal fabric, especially Lenzing Modal is made from beech trees not a mix of softwood, which has been argued leads to deforestation. Lenzing is very committed to the ethical sourcing of their wood and fabrics comes with forest certification for their pulp production Their website claims that they only used sustainably harvested beech trees that are quick growing and regenerative.

Modal uses a closed-loop system. Unlike, viscose rayon where chemicals build up with no place to go, the modal system reuses all the chemicals again and again. So, is modal toxic to the environment? Technically it is. But, because the process takes those toxic chemicals and reuses them instead of releasing into the environment, the process is thought of as eco friendly.

And as a bonus fabric, fabric modal material tends to be even more silk-like and have even better shine and drape than viscose rayon material.

What About Tencel + Lyocell?

Lyocell is a closed loop fiber manufacturing processing method that utilizes dry jet-wet spinning and creates different types of lyocell fabric. There is bamboo lyocell (which we will discuss more in a minute), and also, Lenzing Tencel made from eucalyptus. Lenzing Tencel promises sustainable certification and practices that are traceable. Generic lyocell options do not always have the rigorous compliance and strict supply chain control that Lenzing does. So, when an article promotes unbranded lyocell from a fast fashion company like H&M as “ethical fashion”, it’s probably a bit of greenwashing.

So, Is Rayon Sustainable?

Yes and no. In my opinion, sustainability is on a spectrum. Rayon is more sustainable than petroleum synthetic fibers like polyester and nylon. But, is not as sustainable as organic cotton and hemp.

Case Study - Is Bamboo Rayon Eco or Greenwashing?

Is Bamboo Sustainable?

This gets a little tricky. Bamboo rayon was made popular thanks to bamboo sheets and memory foam. Home goods manufacturers did an amazing marketing job and making it seem like bamboo bedding was the sustainable sleep solution we all needed. Google the best natural or sustainable bed sheets or mattress review and you are guaranteed to find something about bamboo.

Bamboo in its natural form is very sustainable and has antimicrobial properties. But, once it is processed it loses those properties. It then just becomes another manufactured fiber. There are two ways of making bamboo synthetic fabrics the first is under the viscose process, which is not sustainable, the second is under the lyocell fiber method, which is a closed loop system and much more sustainable. You can read more about the two methods here.

Quick Fact - Eucalyptus Is Now GMO

Eucalyptus and lyocell are not the holy grail answer to our rayon prayers, check out this article from the Washington Post about the latest controversy around GMO eucalyptus.

What Happens To Rayon In The Landfill?

Is Rayon Biodegradable?

While greenwashing marketers have us all believing that all rayon is considered environmentally friendly because they are cellulosic fibers, I have to ask one of the most common questions in sustainable fashion - What happens to this stuff after it is produced and when we are done with it? A truly sustainable fiber should create a biodegradable fabric that does not live forever in a landfill.

So, what is really happening when you throw away your rayon clothes?

Yes, rayon is biodegradable. And, some studies show it can actually biodegrade faster than cotton.

Here is a study where rayon, modal, and lyocell were all decomposing. The study found that viscose rayon actually decomposes faster than cotton 6 weeks vs 11 weeks. But, modal and tencel tend to take a bit longer at about 4 months decompose only 1/2 of the fabric.

This is interesting when we talk about what is "the most sustainable". When it comes to viscose vs cotton, cotton is always considered the most sustainable because it is the most natural. Then comes lyocell, modal, and viscose rayon in last place. But, if we are looking at the full product cycle, and what happens to garments after they are worn, then viscose material is actually the most sustainable. I wonder how rayon stacks up when compared to something like wool or linen?

See. This is what I mean by sustainability is a spectrum, and nothing is ever perfect. If you care about where your fibers come from, choose cotton, or organic cotton. If you care about the full product cycle, and where your clothes go after you wear them then maybe viscose is your best choice. The point is, sustainability is personal depending on what is important to you.

But, You Should Still Try To Avoid Throwing Things Away

In the landfill, nothing really ever decomposes, even things that are generally compostable. Fiber made in the most sustainable way will still be around for a very long time. That's just the nature of, and a big problem with landfills. In order for rayons to decompose, they need special and regulated environments.

Can I Compost My Clothes?

I wouldn't. Remember, these fabrics have dyes and chemical finishes on them. Athough the fabrics may disappear into your compost pile, the invisible chemicals do not. Also, most fabrics are not 100% rayon fabric, they are a blend or might have stretch (poly fibers) added - and these fibers do not biodegrade.

You Have Power As A Consumer

If you are looking to edit your closet into a more sustainable one, try these tips when shopping rayon and viscose.

Look Out For Labeling

Especially for the Lenzing trademark on your garments tags and care labels. Brands pay a premium to use Lenzing fibers, they actually cost much more than generics because of rights reserved. Generally, brands don’t miss out on an opportunity to let you know they are using a superior product. Think about it; if you as a consumer don’t know the difference between Lenzing and generic, then why should a brand pay more and cut into their bottom line? Brands want credit when they do the right thing. They are going to take the time to explain and advertise, and one of the easiest ways for them to do that is putting “Lenzing Modal” instead of “modal” on their care tags.

Ask Questions

There is another way to know as a consumer what you are buying. You can always ask a company where they are sourcing from, check out the brands about contact from, and send them an email!.

Buy Second Hand

Try buying second hand to save resources and give clothes a new life.

Questions? Comments? Leave a note in the comments section, or here is our email address to drop us a line!