There are a number of plant-based fibers with silk-like qualities that are available to handspinners and as yarn for knitters.  Most of these fibers are being used for eco-conscious clothing all over the world.  Because they are manufactured, there is some debate about how “natural” these fibers are.  They are not made from plastic or any petroleum product, but the eco-footprint of their manufacture can make them a little bit questionable as far as eco-friendly fibers go.  They are all made using chemicals in one way or another to break down the fibers, then to re-assemble (polymerize) those fibers for extrusion.  Some of those processes carefully reuse the chemicals and don’t allow any into the environment, while other processes allow caustic sodium hydroxide to leach out as waste.

A word about “polymerization”:  I’ve heard people jump to the conclusion that this means there is plastic in these fibers. That isn’t actually the case. No petroleum products are introduced in the reprocessed cellulose or protein fibers. The term “polymerization” is just a description of the chemical process of bonding molecules into a long chain.



Rayon is also known as “viscose,” and is a  fiber made from wood pulp broken down into cellulose bits, polymerized, then extruded into fine, smooth fibers. This mimics the way spiders or silkworms produce their silk, leaving each strand of fiber with a smooth, round surface.  Fabric made with Rayon has a lovely, heavy drape and is comfortable next to the skin, wicking moisture and comfortable in all weather.  It takes dye like any cellulose fiber would, similar to cotton. The fabric known as “rayon” has been around for over a hundred years. Many newer versions of rayon are being made now, but are usually labeled according to their source plant rather than generically as “rayon.”


Bamboo can be produced into two distinct types of fiber.  One type, bamboo linen, (also known as bamboo hemp,) is made very much like other bast fibers such as linen, ramie, or hemp. The stems of the bamboo grass are broken down into strands of fiber, combed and cleaned, and spun into a thread.  It is a labor-intensive process for any type of bast fiber. Bamboo hemp isn’t common. The more popular modern form of bamboo fiber is the bamboo silk, made with the same process as viscose, or rayon.

The increased production of bamboo silk in recent years has raised questions about how ecologically sound it is.  While the bamboo plant is one of the most easily sustainable resources on earth, and growing it requires far less in the way of pesticides or chemicals than cotton does, the production of the silk can involve caustic sodium hydroxide (lye) to break down the fibers, in a process which loses about half of the chemical into the wastewater. There is also concern about factory workers who inhale the fumes, and the long-term health costs of that inhalation.

Recently some manufacturers have been using a different process which is much less toxic and which reuses the chemicals involved.  This process is called the Lyocell process, and was developed for the manufacture of the brand name fiber “Tencel.” Not all bamboo silk labels which process was used to make it, so those adamant about using only eco-friendly fibers may wish to avoid bamboo silk.  There is also some question about the claims that the fiber is anti-microbial, as it has been so heavily processed that those original characteristics of the bamboo plant are unlikely to have survived.


This is a brand name for the lyocell fiber made from eucalyptus tree pulp, broken down with the ecologically sound lyocell process and extruded into a form of viscose.  This cellulose fiber really is friendly to the environment, made with a closed loop cycle which doesn’t dump chemicals in the manufacture.  This is a beautiful rayon, with silky drape and comfortable feel.  The fabric has that great property that most cellulose fibers have, in that it wicks moisture away from skin.


This cellulose fiber is made with the same lyocell process as Tencel and some Bamboo, but the plant source is seaweed.


Another cellulose fiber made with the lyocell process with beechwood as the source of wood pulp.

Banana, Manilla Hemp, or Abaca:banana plant for fiber

This fiber is not made with the rayon extrusion processes but is made with the methods used in bast (stem) fibers like linen or hemp.  Trimming and pruning of the banana plant leaves and stems can be reduced with water by soaking, pounding, and cleaning to release the silky fibers. Different parts of the stem give different qualities of fiber, ranging from a durable fiber suitable for upholstery fabric and towels to fine and silky inner fibers, which are suitable for next-to-the-skin garments.  The same banana fibers are used for making a durable, beautiful paper, known as abaca.


This unusual modern fiber is made with a process similar to rayon, but it is formed from corn. The same process of polymerizing the corn plant protein is used to make bio-degradable corn plastic, as well as corn fiber.  The fiber is soft, similar to silk, but some handspinners say it has a plastic feel to it.


This is another protein fiber reprocessed from milk proteins. Casein, or milk protein, has been used for centuries as a binder in paint.  In the fiber, it is polymerized and extruded.

Soy Silk:

Yet another plant protein fiber, soy silk is a byproduct of tofu manufacture. It is probably the best known of the new reprocessed fibers. Its texture is very much like true silk, and it takes dyes very much like silk.   It is a less expensive alternative for handspinners, and for making silk fusion.

Comments are always welcome here at SlowYarn! Tell us what you think, share your ideas, or comment on the content. Or you can contact me directly at



Copyright © 2013-2023 Kelley Adams. All rights reserved.

All text, photos, and graphics are the property of Kelley Adams unless credit is given to an alternative source.

16 thoughts on “Rayon, Ingeo, Soy Silk, Bamboo, and More!

  1. Thank you for an article that’s easily understood by a non-chemist! Every time I’ve googled to try to learn something about the processes behind these yarns, I end up on some overly informative page that’s more aimed at a professional chemist than at a homebody knitter.

  2. Has anyone tried doing silk fusion with any of the unusual fibers. Can you paint it before or after fusing. What adhesive do you use?

    1. I’ve done silk fusion with soy silk, and it behaves just like real silk but at a much lower cost. I use it for silk fusion classes, in fact, to keep the cost down for my students. I like the Liquitex Fabric Medium as my adhesive. The hand stays soft and fabric-like after drying.

    1. What a great question, David! I haven’t read anything about testing the tensile strength of these fibers. I’ve heard that worm silk has tested “stronger than steel,” but I always wondered how they do any apples to apples comparison with such dissimilar fibers. At least the rayon type extruded fibers are similar enough I might believe a test.

      Anybody read any information about this?

        1. Ravijee, I am not a manufacturer. I’m one of the people who uses the end product! I hope you get some information on making more soy silk. Wishing you all success in your venture!

  3. Hi Kelley,
    Thank you for this informative article. Please would you consider sharing the name of the supplier from which you purchase your soy silk fabric?

    Thank you!

    1. You are quite welcome!

      At this time, Sharon, I rarely purchase fabric, as I am primarily a handspinner. I get my fiber from The Woolery or Paradise Fibers. I did a Google search for “Soy Silk Fabric” and found that there are several sources through If you find a good source, please let me know and I can add links to the Rayon,Ingeo, etc. page for other readers.

  4. Hi Kelly,

    Thank you very much for the detailed article about different fibers. I have been looking for Eco-friendly fabric, this article has helped me find one.

    Thank you !!

  5. Thanks so much for this interessting article. I am Fashion designer living in Germany and I am searching for fabrics made of soy silk or bamboo. Vegan alternative fabrics to save the animals. Do you have an idea, where I could get this? Thanks so much for your answer and best wishes – Susanne

  6. Have anyone know or have any experience in soap making, if so which is a suggestion and company with yhe least chemical if none at all. Thanks in advance

    1. I know a lot of my readers come to this article from the soap-making forum, where someone posted a link. You could try asking there, if you have any connections to them. A Google search for “soap making supplies” reveals several great sounding companies. or both sound interesting. I hope you find what you’re looking for!

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