What Are Natural Fibers?

We gathered some fibers we had on hand for this introduction to natural fibers. The list is nowhere near exhaustive, but it provides examples of common plant and animal spinning fibers.

Amy Clarke Moore Nov 30, 2020 - 4 min read

What Are Natural Fibers? Primary Image

Photos by Joe Coca

Natural fibers occur naturally in nature, naturally. (Sorry. Couldn’t resist.) It seems obvious, but it actually can be confusing. There are manufactured fibers that originate with or incorporate natural materials, but they are made by human hands (as opposed to extruded through our skin—yes, human hair can be spun, and it happens accidentally quite a lot when a piece of your hair falls onto the fiber you’re spinning). Regenerated or manufactured fibers that start with natural products such as bamboo, soy, or milk, for example, are not usually included in the natural fiber category because of the processes that they have to go through to become fiber suitable for spinning. The term natural fiber refers to fibers that come directly from plants or animals.

Plant and Animal

Plant fibers can grow off a seed (such as cotton), from the stem of a plant (such as flax or hemp), or even from the bark of a tree (such as the Western red cedar). Animal fibers come from the hair of animals such as sheep, dogs, llamas, bison (you get the idea—pretty much anything hairy is spinnable), but animal fibers also include the silk spun by worms and spiders—the most common is the silk from Bombyx mori silkworms. (And yes, you can spin spiderwebs—it is just hard to cultivate spider silk.)

Cellulose and Protein

Plant fibers are composed of cellulose, while animal fibers are composed of protein. These chemical and structural differences mean that cellulose and protein fibers react differently when they are exposed to heat, water, soap, and dyes. Whereas extreme temperature changes can cause some protein structures to become permanently interlocked—as in felt—plant fibers can go through the same processes suffering no damage.

Plant and animal fibers also react differently to pH levels. Protein can be damaged by high pH levels (alkaline—think baking soda), but respond well to low pH levels (acid—think vinegar). Soda ash is alkaline and is a common water softener used in many laundry detergents. This is why, when washing wool and other protein fibers, most people encourage the use of wool-safe detergents and a vinegar rinse. Cellulose and protein fibers take dye differently. In most cases, fiber-reactive dyes are used to dye cellulose fibers, and acid dyes are used to dye protein fibers.

A Gallery of Natural Fibers

We photographed some fibers we had on hand. The list is nowhere near exhaustive—it just provides an introduction to natural fibers.

Bast Fibers


Bast fibers, from left: Flax, Hemp.



Camelids, from left: Camel, Alpaca, Llama.



Goat, from left: Cashgora, Cashmere, Cashmere.

Seed Fibers


Seed fibers, from left: Cotton boll, Cotton, Colored cotton.

Sheep Wool


Sheep Wool, clockwise from top left: Masham, Merio, Black Welsh Mountain, Icelandic, Norwegian.



Silk, from left: Silk noil, Tussah, Bombyx.





  • McCuin, Judith MacKenzie. The Intentional Spinner: A Holistic Approach to Making Yarn. Loveland, Colorado: Interweave, 2009.

This article was published in the Winter 2010 issue of Spin Off.