Cotton: Cotton plants are related to hollyhock and hibiscus and are grown in warm climates. Cotton fibres are up to 95 percent pure cellulose and derive from. The white, fluffy fibres grow around the plant's seed pod, or boll. Once mature, the bolls are picked and a cotton gin is used to separate the fibres from the seed. Depending on the variety, cotton fibres vary in staple length and softness, but all are relatively durable. Cotton doesn't insulate well, but is extremely absorbent; fibres can absorb more than twenty times their weight in water, and the water will evaporate quickly. Because of the inelasticity of the fibre, items made from cotton will relax or grow over time, and will need to be reshaped after washing.
Hemp: Hemp is the coarse, durable bast (skeletal or structural) fibre of the high-yield Cannibis sativa plant (the fibre does not contain the chemicals found in the leaves cultivated for medicinal or recreational drug use). Used historically for items such as ropes and ship sails, it also makes extremely strong paper that doesn't require harsh chemical processing to produce. Hemp fabrics can be machine washed and dried, and they soften considerably after laundering.
Jute: One of the strongest natural fibres, jute is the bast fibre of the Corchorus olitorius and Corchorus capsularis plants grown in monsoon climates. Cultivated in India since ancient times, jute is resistant to heat and fire damage and is biodegradable. Due to its coarseness, jute fabric is used primarily for items such as sacs, rugs, upholstery, twine and rope.
Sisal: Originating in the Yucatan Peninsula of Mexico, sisal, like jute, is most often used in ropes, twines, rugs, and other relatively coarse items requiring strength.
Flax: Grown in a variety of climates and soil conditions since ancient times, flax plants yield linen fiber. Linen is a strong, coarse fibre that drapes well and, like other cellulose fibres, is durable but lacks elasticity. The more it is worked with and used, the softer and more lustrous it gets.
Ramie: Ramie is a bast fibre that is mechanically scraped from the bark of the plant, which is a member of the nettle family. Cultivated primarily in China, the fibre has been used in textiles for over 5,000 years, and resists bacteria and fungal damage. Three times more porous than cotton, it breathes extremely well and is thus suited to hot-weather garments. It takes dye well and is often blended with other fibres for yarn construction.
Note: Some have inquired about bamboo. Our research shows that solvents are required to transform the fiber into yarn, and that process does not comply with IYNF standards.
The Intentional Spinner: A Holistic Approach to Making Yarn, by Judith MacKenzie McCuin (Interweave Press, 2008)
The Knitter's Book of Yarn: The Ultimate Guide to Choosing, Using, and Enjoying Yarn; by Clara Parkes (Potter Craft, 2007)