


With so many “eco-friendly” fabrics to choose from, it can feel impossible to unravel which is the better choice. In particular, plant-based natural fabrics have been on the rise in the textile industry in recent years. Despite having been around for many years, soy fabric is a relatively unknown, yet fascinating, fabric that holds its own next to bamboo fabric.
Both bamboo and soy fabrics have their advantages and disadvantages. Bamboo fabric’s breathability and durability make it a great choice for athletic apparel, summer bedding, and undergarments. Meanwhile, the soft cashmere-like soy fabric is ideal for skirts, baby clothing, and upholstery due to its elasticity and ability to drape nicely.
Below, we further compare the two fabrics to find out which one is the better option based on softness, breathability, and more. We’ll also take a closer look at the production process of each fabric (including how the materials are grown) so that you can get a clear sense of their overall sustainability. Let’s dig in!
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Which one is the more eco-friendly fabric: bamboo or soy?
Getting to the bottom of whether or not a fabric is eco-friendly can be tricky because the manufacturing process varies depending on the producer. Unfortunately, as natural materials, bamboo and soy fabric are often subject to greenwashing, where manufacturers describe their product using eco buzz words to make it seem like it is more sustainable than it really is.
This all means you may have to dig deep to find out whether a product is sustainable. When it comes to bamboo and soy fabric, both can be eco-friendly, or not; it depends on how they are produced.
How is bamboo fabric made?
There are several ways that bamboo fabric can be made, and while production processes vary based on the manufacturer, they usually fall into one of two categories: mechanical or chemical.
There are several ways that bamboo fabric can be made, and while production processes vary based on the manufacturer, they usually fall into one of two categories: mechanical or chemical.
During the mechanical process, the woody portion of bamboo material is turned into a mash (wood pulp). Natural enzymes are then added to separate the bamboo fibers before spinning them into bamboo yarn. This creates bamboo linen, a strong, durable, and high-quality fabric that is used for bamboo clothing. However, since this process is very time-consuming, many manufacturers resort to using the chemical method to make bamboo fabric instead.
The chemical process for making bamboo fabric is the one most commonly used by manufacturers. During this process, the bamboo fiber is regenerated into cellulose. The resulting synthetic fibers are a form of rayon, otherwise known as bamboo viscose or modal. Unfortunately, the harsh chemicals used in the rayon process are often toxic which not only endangers workers. It also results in hazardous waste that can pollute the environment. The rayon/viscose process therefore has a bad environmental impact.
Since bamboo rayon is made from bamboo, it is technically a “bamboo fabric.” This is inevitably misleading for consumers; as you can see, not all production methods are created equal. Fortunately, in the United States, the Federal Trade Commission (FTC) requires that manufacturers clearly label their bamboo products as “rayon made from bamboo” rather than “bamboo” if produced using the chemical method.
Note: there is an increasingly popular alternative to bamboo rayon called bamboo lyocell, which uses non-toxic chemicals to break the raw material down into bamboo cellulose. Additionally, this happens in a closed-loop process that recycles the chemicals, resulting in less toxic waste.
How is soy fabric made?
Soy fabric comes from the hulls of the soybean plant (Glycine max), a byproduct of the soybean industry that is otherwise considered waste. To turn the hulls into fibers, they are first processed to isolate soy protein. The protein is then treated to reduce the coarseness, usually either with natural enzymes or alkali. The alkali liquids can be reused like the chemicals used to make lyocell bamboo, but they are considered toxic and can be damaging to the biosphere.
Once the initial treatments are done, the watery soy protein mixture is extruded through spinnerets. Once dry, the resulting fibers are ready to be used. At this point, however, some manufacturers add formaldehyde to increase the durability of the fibers. Formaldehyde is a very toxic substance that poses risks to the environment as well as the health of workers. A slightly safer alternative is polycarboxylic acid, which has been determined to have a more minimal impact on human health and the environment. Finally, the fibers are spun into yarn, at which point they can be dyed if desired.
Fun fact: Henry Ford was an unlikely proponent of soybean fabric in the 1940s. He wished to “combine agriculture with industry” as evidenced by his soybean car and experimentation with soy fabric. Early Ford cars were even upholstered with a blend of soy and wool! World War II suspended the production of automobiles, which put a halt to Ford’s research with soybean material. It wasn’t until 1999 that soy fabric regained popularity for consumer items.
Bamboo vs soy fabric: the main criteria
As you can see, which fabric is more eco-friendly is not as clear-cut as one might hope, as it depends largely on the production processes which vary from manufacturer to manufacturer. Luckily, that’s not the only criteria for comparing bamboo fabric to soy fabric. Let’s take a closer look at some other factors below:
Ecology (which plant is more sustainable to grow?)
When comparing the bamboo plant and the soybean plant, the bamboo plant is much more sustainable to grow for several reasons. Bamboo is one of the fastest-growing grasses on the planet; it’s a perennial grass that does the majority of its growing within its first year and can grow tremendously tall. It requires very little water to thrive and it’s very resistant to pests and fungi, which means it doesn’t need pesticides or fertilizers to grow. Therefore, bamboo is a very renewable resource and the main reason why people believe it’s a sustainable fabric.
By contrast, the soybean plant is quite controversial. Soybeans need a tremendous amount of resources like pesticides and water to grow. Genetic modification is also very common with the soybean plant. Moreover, deforestation is an important issue as forests are cut down to grow more soybeans, which are mostly fed to livestock.
That said, soy fabric is made from the hulls of the soybean plant, which would otherwise be discarded. In other words, soy fabric repurposes waste, which is inherently an eco-friendly practice.
Biodegradability
Determining which fabric is more biodegradable depends on the production process and what has been added. Bamboo rayon is not classified as biodegradable due to the chemical additives, but bamboo linen can start to biodegrade within a year.
Likewise, organic soy fabric without other materials mixed in is also considered biodegradable, although the timeline is less clear. Soy fabrics that are blended with other materials impact their biodegradability.
Breathability
While soy fabric is a breathable material, bamboo textiles have a reputation for being one of the most breathable fabrics on the market, giving it a competitive edge in this category. Soy fabric is highly absorbent and an excellent draping material, making it very comfortable. It is certainly more breathable than organic cotton or polyester.
However, bamboo wins here as it is famous for being a highly breathable fabric. It is ideal for thermoregulation due to its breathability and is a popular choice for athletic apparel and undergarments. It wicks excess moisture away from the skin, which is a quality that soy fabric does not have.
Antibacterial properties
This is another tricky category since bamboo is widely marketed as an antibacterial fabric. However, when chemically processed, bamboo rayon in particular loses bamboo’s natural antibacterial and antimicrobial properties. That said, bamboo linen or bamboo lyocell is still naturally antibacterial.
Soy fabrics are not often marketed as antibacterial, but research suggests that they still carry those properties, particularly due to their high breathability. Since there is less research to confirm that soy is definitively antibacterial, we will give this category to bamboo with a caveat that only if it is bamboo linen.
Softness
This may be the toughest showdown between the two fabrics! Soy fabric is famously nicknamed “vegetable cashmere” since it is a plant-based alternative to cashmere that is just as soft and silky to the touch. On the other hand, bamboo fabric is also renowned for being incredibly soft and comfortable and is a popular choice for bedding.
In terms of thread count, most soy fabrics vary from 100-500. Conversely, bamboo ranges from 300-600, and with a higher thread count will result in a softer fabric. With that said, I’d suggest giving them both a try because it may come down to personal preference when the race is this close.
Durability
When it comes to durability, bamboo is superior. While bamboo is prone to wear and tear over time and prolonged use, one of soy fabric’s major drawbacks is that it is not particularly durable. While it has a better tensile strength than cotton and is a very stretchy fabric, pilling is a big problem with soy fabric, which is often why it is blended with other materials like cotton or wool.
It’s also the reason manufacturers will use formaldehyde in the production process, since it helps make the thread more durable. Soy fabric also struggles with dyes and can bleed during the first few washes, but wrinkles and shrinkage are fortunately not common.
Hypoallergenic properties
Believe it or not, no definitive data suggests that soy fabrics are hypoallergenic. Since soy fabric is not as popular as bamboo, there is minimal research available on its benefits. However, it is very gentle on the skin, soft, and absorbent so it can help prevent certain irritations. Bamboo is widely advertised as a hypoallergenic fabric, so it is most likely the better choice if that concerns you or if you have sensitive skin. With that said, bamboo fabric is only hypoallergenic if it hasn’t been chemically treated.
It’s also worth mentioning that organic soy fabric contains many beneficial amino acids that can be absorbed into the skin. This is a huge benefit, but it may increase the likelihood of an allergic reaction. There’s so much that we still don’t know about soy fabric, and if more research emerges in this area, it could tip the scales in this category.
There are rare cases where people are allergic to soy or bamboo, so it’s always a good idea to test a new fabric first in a safe and controlled way if you are prone to allergies.
Bamboo vs soy fabric: which one is better?
Still undecided? Here is a summary of some of the categories above so you can decide which is best for you:
Category | Bamboo Rating | Soy Rating | Winner |
---|---|---|---|
Sustainability | ★★★ | ★★★★ | Soy: While both can be eco-friendly plant-based fabrics, soy fabric is often made without toxic chemicals (the exception being formaldehyde in the case of some manufacturers) while bamboo rayon (the most popular bamboo fabric) uses harmful chemicals that cause environmental pollution. |
Ecology (which is more sustainable to grow) | ★★★★★ | ★★ | Bamboo: Bamboo plants are much more sustainable to grow due to speed of growth and minimal natural resources required, however, it’s worth noting that soy fabric is made of the waste byproduct of soybean production. |
Breathability | ★★★★★ | ★★★★ | Bamboo: While both materials are very breathable, bamboo fabric is well-known for being one of the most breathable fabrics on the market. |
Antibacterial properties | ★★★ | ★★★★ | Soy: Bamboo has strong anti-bacterial properties if made with lyocell or as bamboo linen. However, rayon bamboo loses its antibacterial capabilities. |
Softness | ★★★★★ | ★★★★★ | Tied: Both types of fabric are consistently soft, though you may be able to find bamboo fabric with a slightly higher (aka softer) thread count. |
Durability | ★★★ | ★★ | Bamboo: While bamboo is not the strongest fabric out there, it is a more durable choice than soy fabric, which is prone to pilling. |
Hypoallergenic properties | ★★★★ | Not enough information to score | Bamboo: While there isn’t enough data to determine whether soy is hypoallergenic, both are gentle on the skin and highly breathable (which can prevent allergic reactions to dust/mold). |
Which is the winner?
Bamboo fabric certainly scored higher on our chart, but with so many variables and variations from manufacturer to manufacturer, the best option is ultimately up to what you value most as a consumer and what you intend to use the material for.
Bamboo may be better for athletic wear, undergarments, and bedding since it is soft, breathable, and durable. However, soy fabrics make beautiful skirts, cardigans, or T-shirts since they are silky soft and drape nicely. It isn’t unreasonable to think that different plant-derived fabrics can be used for different purposes. I’d recommend looking into the individual makers and manufacturers to ensure you get exactly what you are paying for.