There are over 700 species of Eucalyptus trees, most of which grow in Australia. Most species cannot withstand frost. Still, Eucalypts can be found growing in other countries with warm climates. This bark was found shed on the ground in a rest area near Sacramento, California. The smooth-barked Eucalypts shed their bark throughout the year, which makes it easy to harvest. The bark I gathered is referred to as "ribbon" bark because it peels away from the tree in long, thin, curling, ribbon-like strips.
I cut the strips of bark into about 4" lengths, then submersed them in water. This simmered for several hours off and on over a couple of days before entering some wool fiber. No pre-mordanting of the fiber was needed because bark contains natural tannins which act as a mordant.The picture above shows the bark after I had already used it for dyeing. I forgot to take a photo before dyeing, when the bark had a deeper, reddish-brown shade of color. Here the bark looks pretty well spent.
Most of my dyeing is just for experimental purposes so I rarely measure fiber or plant material. I am most interested in just seeing what kind of color is possible. If I were dyeing fiber for a specific project or thought I might want to try to repeat a color, I would take the time to measure. Rule of thumb is to use at least twice the weight of plant material to the weight of fiber.
I began with a handful of white Polworth roving, and a handful of taupe BFL roving, putting each in a net bag large enough to let the dye bath soak all through the fiber. I left the bark in the dye bath to allow the fiber to simmer simultaneously with the bark. They simmered together for 2-4 hours before I turned the heat off and left the dye bath to cool over night. The next day I pulled the fiber out and laid it in the sun to dry. The picture below shows the original, un-dyed fiber at the top. The taupe came out a beautiful chocolate brown, the white a medium tan color, both in the first bath. Another handful of the taupe roving went into a 2nd bath and tuned out just a shade lighter than the first.
Next, I blended the three dyed fibers together using my hand cards.
It makes for lovely spinning!