I tend to work with dried dye plant material rather than fresh. My gardening space is on the small side. Even with ‘weeds’ I rarely have enough fresh material so I’ve been concentrating on plants I can dry and save up over time.
Red and blue aren’t a problem because I can purchase Madder and Indigo already dried. Onion peels (yellow to orange and rust) are dry and easy to store. Usually its the yellows that need some planning. Fennel is my local dryable yellow for wool and Oxalis for cotton (although it works on wool too). The dye books I’ve been reading tend to discuss the plant to dye stuff radio in terms of fresh dye material, often 1:1 (dye material:fiber) or in the case of cotton as much as 2:1 (dye material:fiber). The weight drops quite a bit in the drying so I did some before and after weighing to get a better idea of how much to use.
The dried Oxalis seems to be about 12% of the fresh. Which means 1:1, 2:1 or anything like that is way too much dye material.
Fresh material weighed .9 oz or 25 g
Dried material weighed .1 oz or 3 gm.
For a long time I’ve used my trusty triple beam scale for measuring dye material. This had been given to me by my father. He always used a triple beam scale for measuring ceramic glaze chemicals and it was one of those things he thought I should know how to use correctly, along with tire changing and other useful stuff.
Recently I got my first digital scale. Obviously it must take very little to make me happy. I love the push-button tare function. (Way easier than zeroing out my old standard.) Also being able to switch between metric and that other thing by pushing a button. Even the cats like it.
(before and after)
Cotton samples, 50% and 25% DRIED plant to fiber, and then on the far right extra samples tossed into the 50% and 25% dye soup to exhaust the dye. The extra samples (in order) were wool, soy silk and cotton.
So far my most successful cotton processing has been derived from Jill Goodwin’s “A Dyer’s Manual” – a book both beautiful and useful.
Jill Goodwin method: soak the cotton at least an hour (overnight in this case); “mordant 8 oz of cotton, dissolve 2 oz of alum (60 grams) and half an oz (4 tsp or 20 ml) of washing soda in a pot of boiling water” – ok ounces make my head ache, I use metric for dye work so I calculated this to alum 25% (.25 x weight of fiber) and washing soda 6% (.06 x weight of fiber); boil cotton in alum and washing soda for half an hour, stir occasionally.
I simmered the dried oxalis (contained in a pantyhose foot) and the cotton for about an hour and cooled overnight, around 24 hours.
Goodwin suggests that you use 2x the weight of the material to be dyed. however I have found that dried dye material is quite a bit stronger (concentrated?) then fresh. The color on the photo I have posted here is definately not perfect but gives a general idea of the color. The fiber is darker in the dye liquid but even after the washout I had a decent medium and deep yellow. I plan to try a 10% for a lighter yellow.
The surprise was the amount of color left in the dye liquid that was picked up by the wool, soy silk and 2nd cotton samples. The light yellow samples I will probably over dye with indigo.
In the area of Southern California where I live, Oxalis is one of those frighteningly hearty and unstoppable plants that appear wanted or not. On the positive side, this is one of the few local plants I’ve found that works well on cotton and produces a nice bright yellow. (Samples on the way). And the bees really seem to enjoy it.
The Oxalis reappeared this year around late November. Generally as soon as it shows up I start picking and drying it (paper bag hanging in the hall near our floor heater vent) so there is enough on hand for a decent dye bath.
Oxalis fresh, and dried.