The SAFF fun continues! I mentioned that Noob and I happened to end up in the same class as TrailingYarn Saturday. The class was on techniques for coloring fiber from plants you might find in your own backyard. Noob and I had no previous experience with dyeing yarn or fiber prior to attending this class, so we were excited to learn a "greener" technique first. Well my friends, it's not completely green, but as close as you can get I'm sure.
What is a natural dye? To the best of my knowledge, a natural dye is one found in nature and can be extracted and absorbed by a fiber or yarn with the use of a mordant. This is different than a natural stain, like a grass stain, which does not penetrate the fiber throughout, but instead stays on the surface of the fiber. Stains also fade or wash out eventually. Dyes do not.
Dyes can come from almost any plant and in any color, but in the Southeast yellows and green dominate. Though sources for shades of brown and purples (including some red) can be found. I am sticking with the 6 sources we used, because obviously I am the most versed in those. In the picture above Goldenrod, Black walnuts (in their husks), Oak leaves, Pokeberries and Marigolds were all used. We also briefly examined some onion skin dyes. For those of you getting excited, the color of the onion, such as purple, skin made no difference; The onion still produced a color somewhere between the brown walnut color and the beige oak leaf color.
The dye is extracted by heating a large pot of water and a mordant (we used Alum) with the plant for a long period of time. The type of water you use in the heating step may affect the color based on it's additives. Distilled water theoretically contains no additives, well water contains the same additives as found in the soil around it and tap water contains additives such chlorine and fluorine based on your city. It would be interesting to see which effects each type of water has, if you had access to all three while dyeing.
The mordant you choose also affects the final color of your dye. Iron mutes the color, and Tin brightens it for example. I pause here to say that mordants are toxic, because it is a salt combined with a metal in our case Aluminum. Alum is toxic in quantities over an ounce. You can use other metals such as Copper, Zinc, Tin, Chrome, and Iron to name a few, but the heavier the metal the more toxic it is to you. This is why some natural dyes aren't completely green, per say. It is important to correctly measure the mordant to dye ratio. Ideally, the dye would use up all the mordant in your pot, leaving the water safe to pout out down the sink, into house plants, in the yard, etc. Luckily, not all plant dye extracts require a mordant or a mordant as strong as the metals listed above. Vinegar is also a mild mordant. The pokeberries did not require a mordant stronger than simmering in a large vat of vinegar. The black walnuts we stewed required no additives other than themselves and the water they were heated in. The same with the onion peels.
Once our water/mordant/plant mixture was sufficiently heated we whetted unskeined, but still tied yarns to the pot. This will give you a semisolid dye job. You could use a wicking method, where one third of the yarn is submerged and the other two thirds is left hanging over the edge to wick up the color. This produces a variegated yarn, ranging in shades of one color from dark (in the pot) to light (the opposite end). With both methods the longer you "stew" your brew, the more color extracted from the plant and absorbed by your yarn.
The next step is is rinse you yarn. You do not want to go from hot to cold immediately or the yarn will felt, so I've been told. We lifted the yarn pot of the pot, gave it some gentle squeezes and set it aside in a bucket to cool. At this point, the yarn appears to be a much darker color than it actually is, we were warned that in the rinsing phase removes a lot of the color and it does. You may want to wear gloves at this stage, black walnuts and pokeberries will dye your skin for the next few days. Once the fiber is rinsed lay it out to dry before reskeining.
One final note, natural dyes are just that, natural. Sunlight, time and environment can affect their color over time, just as they would affect the original plant. So, make sure to store your valuables away from their natural predators, like yarn chewing cats and direct sun.