Continuing on with our yarn fiber series, (see also eco-friendly yarns and bio-synthetic yarns) this week we delve into plant fibers. Plant fibers are derived either from leaves, stems (known as bast fibers), or seeds of plants. Cotton is a seed fiber produced from the cotton boll, and ramie, linen and flax are bast fibers. Leaf fibers are not often found in yarn but would include sisal (from agave plant) and pina (from pineapple) and banana.
Cotton, often identified by the region from whence it comes (think Egyptian cotton), primarily comes to us from India, Africa and the Americas. Flax is grown in many places but primarily in Western Europe. Ramie is one of the world’s oldest crops (a flowering shrub in the nettle family), primarily produced in China. According to Wikipedia Ramie is the fiber of the mummy cloths found in the tombs of Egypt.
Plant fiber yarns are made by first separating the fibers from the plant. In the case of cotton, the fibers are found in the boll and are relatively short to begin with (about 1 – 1 3/4″ long). Fibers are separated from the boll by machines at the mill, washed, and carded resulting in what is called a “sliver”. Spinning machines use fibers from the sliver to spin the yarn.
Processes used for separating bast fibers are far more complex in order to separate the fibers from the plant stems. For example, the process for producing flax/linen (linen comes from the flax plant) is . Fibers are separated from the plants through “rippling”, “retting”, rolling, breaking and scutching processes. eHow.com has a good article describing the process in more detail however, in summary, the rippling process removes the seeds, and the retting process involves soaking the plants in acids or chemicals to dissolve the stalk from the fiber within. Once retted, and dried, the plants are then put through the next machine that crushes and breaks the stalks into “shives”. Shives are sent on to a scutching machine that at last, separates the fiber. Those fibers are then combed, straightened and sorted by length. (Phew, there’s a lot to this business of producing linen!) Once sorted by length (now called “slivers”) they are pressed into rovings which can then be spun. The longer the fibers, the finer the end product and vice versa, the shorter fibers result in coarser yarn.
In general, plant yarns are cool and absorbent, drapey, and non-insulating making them a really great choice for summer wear however, there are a few characteristics to keep in mind.
They are typically “harder” than animal fibers, can have a rougher hand and in some cases, can be downright difficult to work with. They don’t have the loft or memory of a wool, are inelastic (impacts your ribbing) and can lengthen when hung. Be careful of lengthening since lengthening changes the gauge (your piece gets longer and narrower).
Plant Fiber Yarn Properties
Cotton I’m certain as I write this that you are already familiar with cotton, as it is so well known however, as a yarn, there are a few things to keep in mind if you plan to knit with it. When compared with wool, cotton is stronger and less itchy providing a good alternative for those who have allergies to animal fibers. Cotton does maintain its shape very well so look to your pattern for any draping that you want to create.
One thing to keep in mind when planning around cotton yarn is its in-elasticity. Cotton ribbing will not be as elastic as wool ribbing for example. If you are concerned about the environment, the cotton industry has taken quite a bit of flack of late due to the use of pesticides however, there are many organic cotton yarns available today.
Brands/Where to buy? I would hazard a guess to say that ALL yarn suppliers offer cotton and cotton blend yarns making it very easy to find. Just check your LYS and if you do need additional sources (for specific weight or color for instance) you can try any of the major yarn manufacturers online such as Crystal Palace, Rowan, or Paton to find a source. Likewise, most online yarn vendors have offerings available (e.g. KnitPicks, Yarn Barn, WEBS).
Flax/Linen Flax and linen fibers are stronger than cotton and like cotton, are inelastic. Those of you who love to wear linen in the warmer months are already aware of linen’s propensity to crease.
Brands/Where to buy? Like cotton, flax and linens are easily found. Rowan, Plymouth Yarns and Berroco all offer linen yarns. If you have difficulties, try the online resources I’ve given above for cotton.
Hemp Hemp is a very strong fiber, is 100% bio-degradable and like other bast fibers, is inelastic. It can be very stiff (you’re probably familiar with hemp’s use in ropes) however, and therefore somewhat difficult to work with. It is also expensive to produce thus, you’ll find it more often as part of a blend.
Brands/Where to Buy? More often than not, you’ll be looking for a blend however, I have seen hemp in eco-friendly yarn stores if you have one near you. You can also find hemp (100% and in blends) online at LanaKnits, and at WEBS.
Ramie Like hemp, ramie can be stiff and brittle however, it can also be quite lustrous. It does not dye as well as cotton, is not as durable but holds its shape well and resists wrinkling. Since it is not as durable, it is most often found in blends.
Brands/Where to buy? This one is a bit tougher. I had a difficult time finding ramie yarn at the usual places. Most of the suppliers listed are importers from China. If you are interested in finding and trying ramie, let me know and I’ll try to help you find some. If you do have a source, please let us know and we’ll provide updates to this blog.
What has your experience been knitting with plant fibers? Please let me know what you think in the comments below. Next up are the animal fibers, my favorite.