I started my Fiber Feature series by talking about the plant based fibers since we're moving into the warmer months of the year and fewer people are familiar with these yarns. Now that I've covered the most common plant based fibers and briefly discussed synthetic fibers I will be moving on to the various protein fibers. But before I do, I want to talk a little about working with plant based fibers.
Cellulose based fibers (and many synthetics) all have a fundamental structural difference from protein based fibers that can be disconcerting to many knitters the first time they work with them. The surfaces of plant fibers are smooth, unlike animal fibers that have scales. The microscopic scales of animal fibers help the fibers hang together better, give the fibers elasticity, plus they allow air space within the fiber which helps to hold in warmth. Without scales the fibers move past each other easily, making the yarn slippery and the fibers are more densely packed together, not allowing air and therefore heat to be trapped. These factors give plant fibers their wonderful drape and coolness next to the skin.
Without scales that contribute to protein fiber's elasticity, plant fibers have less elasticity, as a result they are less forgiving of irregularities in tension. This has caused all kinds of frustration for knitters and I've seen some even give up before they've finished a project because they don't like how their project looks. Please don't do that! Here's the thing, once you've finished your project and wash it, a wonderful thing happens! Blooming!!!
During the process of making yarns various treatments are used to make the spinning process more efficient and consistent. These treatments cause the plant fibers to pack together more densely and smooth out what little elasticity the fibers have. We use similar treatments when we iron like sizing and starch. Once you wash the fiber it "blooms" or plumps up in diameter and does shorten some in length. Blooming smooths out minor irregularities in knitting tension, softens the fibers, and changes the gauge. I always strongly encourage anyone I'm helping to always wash or at least thoroughly steam their gauge swatch, particularly when working with plant fibers. Then they will know what to expect and not knit the wrong gauge thinking the yarn is thinner that it really is. Trust me! With most cellulose based yarns washing will make a huge difference in how your garment looks, usually for the better.
So don't get frustrated, just have patience. If you really want to see how your project will look wash that swatch in the same manner you will be washing the finished item. Sewers have known this for decades, when working with cottons always wash them before you start (unless you want the effect of shrinking). Somehow this hasn't translated to knitters, after all we are making fabric!
I hope you find this useful! Please don't hesitate to ask questions or send suggestion to me at askTerry (at) jimmybeanswool (dot) com