Fibers, Part 3a: Cellulosic Fibers – BAST

I took a break from this series due to the summer heat, visitors and vacations.  Now that the weather is cooling … 🙂

Natural cellulosic fibers (also called cellulose fibers), come in three forms, one of which is bast.  Bast fibers include flax, ramie, hemp, jute and kenaf.

The plants that provide us bast fibers are usually tall, requiring stiff stalk fibers to stay up.  Bast fibers are collected from the inner bark (called phloem) that surrounds the stem.  A concoction of pectins, gums and waxes seal together the bast fibers.  Before being able to use the bast fibers, that concoction must be dissolved.

eraseDewRettingA bacterial process called retting is used to do that and is done in (1) fields (aka land or dew retting), (2) bonds or pools (3) tanks, or (4) with chemicals (e.g., sodium hydroxide aka caustic soda or lye).  The picture to the right is of flax undergoing dew retting from Sweden’s Ingeborrap Folk Museum.)


After the retting process (and washing and drying), is scutching.  This removes material from the fibers and separates the fibers from each other.  Once done by knives or swords (as demonstrated by the Ingeborrap Folk Museum), nowadays the eraseScutchingmachinestalks are put between metal rollers.  The scutching machine produces a thick roll of flax called a “lap” (pic from University of Leeds).

eraseOldscutchingmachineOf course, scutching machines go back a ways, as captured by the picture of “Brasier’s treble-patent Breaking and Scutching Machinery.”  The scutching machine was invented in 1797 by Neil Snodgrass of Johnstone (near Glasgow), Scotland but not patented. It was later improved (and patented) by William and Andrew Crighton of Manchester.

eraseHacklingNext, hackling removes short and irregular fibers and puts the fibers in a parallel layout.

New Hampshire Heritage and Traditional Arts demonstrates the process near one of the only known flax retting ponds in the state:

The flax retting pond is man made with the bottom lined with rocks so the flax could be laid out on the rocks, and then weighted down with clumps of sod to prevent the straw from floating to the surface. The natural microorganisms in the pond create the perfect environment for a retting process that can take 4-6 days- which is much quicker than the month it usually takes for dew retting out in a field.  



Long popular with fiber artists and crafters, linen is the fiber made from flax.  Archeologists, in fact, have found pieces of linen in prehistoric dwellings in Switzerland and as well as mummy cloths several thousand years old in Egypt.  Flax has always provided more than just fiber, however.  As noted by Libeco (a company that accounts for more than 60% of total Belgian linen production and sits between Bruges and the French border):

Always ecologically-correct, every part of the flax plant is at man’s service. The seeds provide oil for dyes, paint, cosmetics and floor coverings. When ground, they form a flour used in poultices. The fibers have been used as sutures. The by-products of linen production are processed into a pulp used for banknotes or fiberboard. However, flax is most renowned as the raw material for an extraordinary fabric.

eraseHempProcessingHemp is processed similarly.  It resembles flax but is not as fine as the better quality flax and thus was never popularly used for clothing.  Though not elastic or pliable, it is very strong and does not rot easily in water.   Thus, it was a great fiber to use for twine, ropes and cords.

erase_hempfieldFor those who wonder about the relationship between hemp and marijuana (and that’s a picture of a hemp field in France), hemp “is a commonly used term for high-growing varieties of the Cannabis plant and its products, which include fiber, oil, and seed. Hemp is refined into products such as hemp seed foods, hemp oil, wax, resin, rope, cloth, pulp, paper, and fuel.  Other variants of the herb Cannabis sativa are widely used as a drug, commonly known as marijuana.”  (Wikipedia)

erase_raimieRamie (aka grasscloth or reah) too has a history that goes back many thousands years.  comes from a plant is in the nettle family and needs hot, humid climates.  Its fibers are separated from the stalk by decortication while the plants are fresh (not dried out).  Though the ramie plant has white hairs on its underside, they do not sting!

As it is not a durable fiber, usually ramie is blended with other fibers.  It is similar to linen in absorbency and density but doesn’t dye as well as cotton.  Though it is resistant to insects, rotting and mildew (!), it is not a fiber you want to use to make linens:  Because it has a high molecular crystallinity it isn’t resilient or elastic.  Ramie is stiff and brittle and will break if folded repeatedly in the same place.

eraseJuterettingJute is one of the cheapest textile fibers you will find.  (Pic of retting jute from Wikipedia Commons.)  Its fibers, however, are short and brittle, so it is weak.  Mostly jute is used to make burlap bags for sugar and coffee, carpet backing, rope and twine.  To read more about jute, visit India’s Office of the Jute Commissioner.

erase_kenafLastly is kenaf.  Its leaves are edible but it, like jute, is used mostly for burlap bags, twines, ropes, paper and various industrial purposes.  And its plants grow high, as seen by the picture to the right.

Kenaf is cultivated in many countries, including the U.S. (though in the US mostly for animal bedding and feed).  Its fiber has many uses, including (but not limited to), for making wood, insulation,  soil-less potting mixes, packing material, and material that absorbs oil and liquids.  Ford and BMW, in fact, are making the material for the automobile bodies in part from kenaf.

erase_KenafSeedPodsIts seeds yield an edible vegetable oil that is high in omega polyunsaturated fatty acids, both necessary for normal growth and health and important for reducing cholesterol and heart disease.

And kenaf has pretty amazing seed pods! (pic source)



About sweatyknitter

Fiber art devotee, author, and amateur artisan bread baker.
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10 Responses to Fibers, Part 3a: Cellulosic Fibers – BAST

  1. Thank you for stopping by and reading! >


  2. soknitsome says:

    Very interesting, thank you!


  3. bethy40 says:

    Since flax can be retted by just lying in a field in the dew or by lying in water I always imagined that the retting part just happened naturally. Maybe some curious person(s) saw it already retting and started to play with it and noticed the strong fibers within. Long live tinkering 🙂

    Judith MacKenzie talks a lot about nettle at the beginning of her book The Intentional Spinner. She differentiated it from ramie and talked about all the properties that made it a very common prehistoric textile. Do you have any sources where I could read about it further? Great series! I love articles like this.


  4. lizseville says:

    Very interesting to learn more about this. Thank you.


  5. A result of a lot of trial & errors? 🙂



  6. Neither had I – until I started digging into all about cellulose fibers. 🙂 I have never heard of a fiber artist/crafter using it but I thought I should include it anyway. 🙂



  7. An appropriate post for warm weather! I’d never heard of kenaf before; very interesting!


  8. Rebecca says:

    With all that must be done to flax, I always wonder just how it came to be found to be useful. Seems like more than serendipitous accident doesn’t it.


  9. jengolightly says:



  10. Thank you for a very informative article.


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