What Is Modal Fabric - How It’s Made + Used

Today, modal fabric is used as a sustainable and vegan silk alternative. For many brands that want to offer more affordable, sustainable options to their customers - modal fabric makes that possible without compromising a luxurious look and feel. But, there is a secret to substituting modal for silk. And, it’s understanding that not all modals are the same. Don’t worry, I am going to give you the cheat code. Let’s start from the beginning - what is modal fabric? And what is the material used in?

BUT BEFORE WE GET STARTED...

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WHAT YOU’LL LEARN

1. What is modal fiber?
2. Evolution of rayons and the invention of modal
3. How is modal fabric made?
4. Properties of modal fabrics 
1. stretch
2. feel
3. shrinkage
4. absorbency
5. wrinkle
6. hot and cold weather
7. Washing and care instructions
5. Should you use modal in your clothing line? 
1. 4 pros of modal
2. 3 cons of modal
6. This or that?
1. Viscose vs modal
2. Tencel vs modal
3. Modal vs cotton
4. Modal vs polyester
7. Is the Lenzing modal better? 
8. Is modal really sustainable? 
9. Where to buy modal fabric
10. Additional fiber resources 

NO TIME TO READ? CHECK OUT THIS 60 SECOND SLIDE DECK 

 

WHAT IS MODAL FIBER

FIBER VS. FABRIC 

All fabrics are made up of fibers. 

Fibers are single strands about the width of a human hair. These fibers can be natural like cotton and silk, or man-made like modal and Tencel. The fibers are then spun together into a yarn. And from there the yarns are combined to form a fabric through weaving or knitting. 

Modal is a fiber. And modal fibers make up a modal fabric. 

You can have modal knit fabrics and modal woven fabrics.

Think of it this way, modal is like eggs. An egg is an egg. But with that egg you can make all sorts of dishes - scrambled eggs, an omelet, poached, etc.

That’s exactly the relationship between fibers and fabrics.

MODAL VS RAYON

But, modal fiber is also a type of rayon.  

Confusing right?

Rayon is the umbrella term for different man made semi-synthetic fibers that are made out of cellulose (plant material). Other types of rayon include Tencel, Lyocell, Viscose, and Bamboo fabric.

Another term for rayon fibers is regenerated cellulosic fiber (not to be confused with regenerative farming, which is a totally different thing).

HISTORY AND INVENTION OF MODAL FABRIC

Fiber science is an evolution. It is constantly changing, especially today with new technologies and variations being discovered regularly. Modal is an extension of that evolution. 

First came the invention of viscose, which was then improved, and modal was invented. Modal fabric is considered second-generation viscose (Tencel and lyocell are third-generation). 

While many people think of viscose as an alternative to cotton, it was actually invented by French scientist Hilaire de Chardonnet as an alternative to silk. The first viscose was extremely flammable and had to be recalled from the market because it was just too dangerous. This led to the German Bemberg Company developing a less flammable and more consumer-friendly variation. While the Bemberg Company just wanted to make something that wouldn’t explode into flames while cooking breakfast, the inventors of modal (in Japan in 1951) set out to create a more sustainable option. 

HOW IS MODAL FIBER MADE?

The scientific process. Yea, this might be a bit boring. I mean, we are here for fashion, not science, right? But, understanding this process will help you understand the sustainable advances in modal rayon, as well as some greenwashing to avoid. So, bear with me.

Step 1 – Gathering Cellulose

What is modal fabric made out of? 

In modal, the source of the cellulose (plant material) is beech trees. The reason beech trees were chosen for modal is because they propagate easily. Meaning, they are very easy to grow. Theoretically, you can take a branch from a birch tree, stick it in the ground, and grow another one. And, birch trees also grow very quickly – they don’t take the centuries that great oaks take. This makes birch an ideal sustainable source of cellulose. It can be regrown easily and quickly, preventing deforestation from tropical rainforest areas. 

Step 2 - The Wood Pulp Breakdown

This part of the production process is not so earth friendly. In this step, the wood pulp is broken down. First into tiny wood chips, then into a liquid with the help of some pretty harsh chemicals - sodium hydroxide used.

Step 3 - Liquid Modal

More chemicals - carbon disulfate - is added to make a liquid modal fiber. And a chemical reaction takes place to create and orange substance called sodium cellulose xanthate. 

We'll get more into all the chemicals used in a little bit.

Step 4 - Extrusion

The liquid modal fiber is then pushed through a spinneret, something that looks like a mini shower head, into another chemical solution - this time sulfuric acid. This causes the orange chemical solution to solidify, creating fibers.

Step 5 - Repeat

Then, the process is repeated with some of the waste. Modal was the first fiber to attempt a closed-loop model. Meaning, the waste of the process could go back into the system to make more of the fiber. 

Modal is not a perfect closed-loop system; while some waste produced can go back into the system, not all of it can. That is why modal production is often referred to as a semi-closed loop system. 

While this is much more environmentally friendly than traditional viscose, third-generation lyocell was able to completely close the loop, making an even more sustainable product.

WHERE IS MODAL FABRIC MADE?

Modal fabric is made all over the world, but production hubs are located in Austria, China, and even the United States.

MODAL FABRIC PROPERTIES

What does modal fabric feel like?

Is modal fabric stretchy?

Modal fibers on their own are not very stretchy. But, you can make them stretchy through fabric construction. Knit fabrics tend to have a lot of natural engineered stretch in them. So a knit modal fabric, compared to a woven modal fabric will be more stretchy. 

If more stretch is needed then it is possible through fabric design - elastic, spandex, or lycra which are fibers with natural stretch in them, can be added.

How does modal fabric feel?

Modal fabric manufactured from beech trees feels similar to silk or synthetic bamboo fabric. It is slick, shiny, and tends to have a cooler feel. 

Does modal fabric shrink?

Modal fibers are very stable and tend not to shrink. But (And, this is a big ‘but’) just because a fiber does not shrink that does not mean a fabric won’t. 

When fabrics are knit or woven into textiles the yarns that make them are stretched. After the textiles come off the machines, they relax a little, meaning they shrink a little. Then, when water is added (think washing), they relax even more, and shrink even more. Knit fabrics (mentioned above for their stretch), tend to shrink a lot when washed for the first time. 

So, be careful. Just because modal itself does not shrink, that does not mean your shirt won't.

Is modal fabric breathable?

Yes. Modal is very breathable and performs similarly to cotton. 

The trick to assessing if a fabric is breathable or not is looking at if it absorbent. Fabrics that have higher absorbancy rates, tend to be more breathable. 

Does modal fabric wrinkle?

When it comes to wrinkles, modal is pretty middle ground. Cotton and linen tend to wrinkle more, but modal is not as wrinkle resistant as polyester. 

If you want a wrinkle resistant modal, I would recommend using a knit fabric instead of a woven one. That is because, in general, knit fabrics tend to wrinkle less than wovens.

Is modal fabric warm?

Modal fibers do not offer much insulation, so they are not good for cold weather. 

They do offer good wicking capabilities, which make them a great choice for warm weather. The secret to good fabrics for hot weather is not just fabrics that absorb sweat, but fabrics that can wick (meaning move) the moisture away from the body, and disperse moisture, to help it evaporate quickly.  That cool feeling comes from evaporation.  

How do you wash modal fiber?

Washing and care instructions for modal fabric will depend on the knit, weave, and other manufacturing details. But as a good rule of thumb, wash in cold water, and dry on delicate. Modal fibers can be steamed and ironed, but try to use a low setting to not damage the fibers with excessive heat.

SHOULD YOU USE MODAL IN YOUR CLOTHING DESIGNS? 

To figure out if using modal fabric is the right choice for you, I want to tell you about a few modal fabrics pros and cons. Let’s start with the pros.

MODAL FABRIC PROS

It’s a Good Financial Alternative to Silk

Today modal is used as a silk alternative for both price and ethics. Modal is a fraction of the price of real silk. For example, the same dress that would be about $25 to produce in modal, would cost about $50 or more to make in silk. That’s a huge difference.

It’s Vegan

The other pro to using Modal is that it is vegan. If you didn’t know, there is a lot of crossover between the sustainable and vegan fashion spaces. By using a vegan option, brands are able to appeal to a wider customer base.

It Does Not Contribute to Deforestation

While the use of viscose was a step in the right direction (in my humble opinion), like everything, it is not perfect. And, one of the biggest issues with viscose is that it could be contributing to deforestation. However, with modal, specifically the Austrian company Lenzing’s modal, there tends to be much more transparency in the supply chain. Lenzing is one of the biggest suppliers of modal in the world. The company works hard to eliminate deforestation and verify where all its cellulose is coming from. And, because modal is only using birch trees and not any old type of tree, like viscose rayon, the process of verification and tightening the supply chain tends to be easier. 

It has High Wet Modulus (HWM)

One of the downsides to using viscose is that it tends to stretch out, especially when wet. That makes washing and caring for viscose difficult. High wet modulus, or HWM means that a fiber is actually stronger when wet. In the case of modal, it is about 50% stronger when wet. That means that it is a lot easier to wash and care for modal than viscose. And, in the world of sustainable fashion, that is a really good thing. Because the easier a garment is to wash, the longer it will last, and the longer it lasts, the less likely it is to end up in a landfill. 

Modal tends to be easy to dye because of the fiber’s high absorption rate (how fast it sucks that dye right up). There also tends to be less damage (read money lost) during the dying process because of the increased strength.

CONS OF MODAL

It Still Uses Chemicals 

Many people believe that rayons are natural because they are made from plants. But, as I explained earlier, a lot of chemicals go into the fiber manufacturing process. 

SODIUM HYDROXIDE

Sodium hydroxide is just one example of those chemicals. High concentrations of sodium hydroxide have been known to cause burns to the eyes, skin, digestive system, and lungs. And, prolonged exposure can cause permanent damage, and in some cases death. Sodium hydroxide is also harmful to aquatic life. That is because when sodium hydroxide comes in contact with water, it creates an exothermic reaction. Meaning it makes the water hot. Sometimes too hot for marine animals to survive. 

CARBON DISULFIDE

There is also use of carbon disulfide. Workers exposed to carbon disulfide have complained of dizziness, poor sleep, headaches, anxiety, lack of appetite from stomach problems, and vision changes when inhaled. It is also believed the chemical can cause harm to the eyes, kidneys, heart, liver, nerves and skin. 

SULFURIC ACID

Exposure to sulfuric acid can cause pulmonary edema – or a build-up of fluid in the lungs, which is a medical emergency. Repeated exposure can cause permanent damage. While the way we handle these chemicals has improved through the years to protect the works in manufacturing plants, it is still important to remember that these are some heavy-duty chemicals, and in the wrong hands or without the proper safety guidance can cause serious lifelong problems.

It is Super Absorbent

While this is pro for the dying process, as mentioned above. It can be a negative for garment wearability and comfort. If you have ever noticed, sometimes when you are super hot, and sweating a lot, your cotton shirt might feel really heavy. That is because all of the sweat from your body is quickly absorbing into the shirt like a sponge. So, you could understand why modal would be a terrible choice of fiber for swim and athletic wear.

It Pills and Snags

Many online articles are reporting that modal does not pill. And, that simply is not the case. 

I have run dozens of clothing programs that use modal fabric. And one of the things I always discuss with my clients is that while the fabric looks beautiful straight out of the factory, there might be some complaints in the future after the customer washes it a few times. 

There are also newer modals that tend to pill less. Make sure to be very clear with your development and manufacturing team that you want an option engineered to pill less.

WHEN IS MODAL APPROPRIATE IN YOUR GARMENT DESIGN?

 

Many brands get confused about what fibers they should use for what type of products. So, I am going to break that down quickly for you. 

Because, here is the thing. You can have the nicest garment design, but if you use the wrong fibers and fabrics, it will be a disaster. So, for all of these examples, let’s pretend we are designing a dress, and then decide which fiber would be best for the design.

VISCOSE VS MODAL

The first thing to remember is that viscose and modal are both rayons. But, they have some different properties. Modal tends to have a silkier feel than viscose, and it also tends to be more breathable. Generally speaking, modal tends to have a more luxurious feel than viscose, and it also tends to be more expensive. 

Our dress example: Both viscose and modal are going to create a very flowy breezy dress. But, if you are concerned with comfort, especially in hot weather, you would want to opt for modal. 

Also, if you want a more luxury product (read, sell for more money), modal does tend to have a more luxurious feel and appearance than viscose. 

TENCEL VS MODAL

Again, modal and Tencel are both different types of rayon. But, while modal mimics silk, Tencel tends to feel more like cotton. Except, a more comfy cotton.

Our dress example: Modal and tencel are both going to offer a lot of movement and flowyness in the fabric. But, if you want the fabric to have higher shine, and feel more like silk, you should choose modal. 

If you want the dress to have more of that cozy cotton feel, then choose Tencel.

MODAL FABRIC VS COTTON

Modal is a semi-synthetic rayon that was created to feel like silk. Cotton is a natural fabric that tends to feel a little more rugged. Naturally, cotton has a much stiffer handfeel than modal.

Our dress example: A dress made with cotton will be more rigid, and tend to have a lot more structure (think a woven button-down poplin shirt). Whereas, a dress made with modal will be flowy with movement or a light breeze. 

MODAL FABRIC VS POLYESTER

Modal and poly are both going to offer shine and drape comparable to silk. Generally, polyester is considered an easy care fabric. Meaning it does not wrinkle, and is very easy to wash. The downside to polyester though, is that it is basically a plastic and tends not to breath well – meaning it isn’t great for the heat. 

Our dress example: If you want something that will not wrinkle (thinking packing in a suitcase for vacation) polyester is going to be your best bet. But, it’s also going to be hot and sweaty.

If you also want the dress to be comfortable, especially in hot weather, I would pick modal (just remember to pack a steamer for those wrinkles). 

Also, from a sustainability standpoint modal fabric is the clear winner here.

IS PAYING MORE FOR LENZING FIBERS WORTH IT?

In my opinion, yes. 

You don’t just get the traceability of the brand, you also get tons of technological innovations that were meant to solve problems and help you create the best product possible. That is because, Lenzing doesn’t just make 1 type of modal – they actually make 9 different types (as of April 2023). 

A few of my favorites…

These different types of fibers aim to solve different problems for the customer. Lenzing micro technology is used to make modal micro and modal micro air. This technology produces finer and lighter fibers that are better suited for athletic wear. 

Lenzing eco color technology creates modal color and modal color black. These fibers are a special set of options that come in premade color options. The color is actually added into the liquid mix, before it is turned into solid fibers. The benefit to this type of technology is that there is no additional dying process – meaning it saves a TON (literally) of water and energy. The downside is, brands must choose from a predetermined set of colors. But another benefit to this technology is that it tends to have better color retention (meaning will not fade) compared to other traditional dye methods. The color black is notorious for fading, so the fact that Lenzing makes a special black option is noteworthy. And, Lenzing indigo color, is just what it sounds like an indigo denim modal option.

IS MODAL REALLY SUSTAINABLE?

I saved this for the end. Because, to answer it you need to understand all the ins and outs, and pros and cons of using it. The thing is, sustainability isn’t black and white. It isn’t good and bad. Sustainability is about doing the best you can. 

So, if you are using polyester for a dress, and can use modal then ya, it’s probably a more sustainable option. But, if using modal, like in the example of swimwear, creates a lower quality product, something that people won’t like using, and will just leave in their closets, ultimately end up in a landfill, then, no it’s not.

At the end of the day if something is sustainable or not is determined by you and your values, not what a magazine article says.

There you go! All of the secrets have been revealed. Once you understand everything there is to know about modal, and by now you do, it’s really up to you if you consider an option for you or not. Remember, there is no right or wrong answer.

WHERE TO BUY MODAL FABRIC

BEST PLACES TO BUY SUSTAINABLE MODAL FABRIC

Lenzing

Global tradeshows 

ADDITIONAL FIBER RESOURCES 

What is rayon

What is polyester

Recycled cotton

What is tencel lyocell, and is it sustainable? 

DO YOU PLAN TO USE MODAL IN YOUR FASHION BRAND? 

Sustainable clothing brands, let me know in the comments - what do you think now that you really understand, what is modal fabric? Are you going to use it in your line?