The first batch of indigo was a small trial batch on 15L because I heard so much about the difficulties with indigo and that it was supposedly a lot trickier than e.g. madder and onion skin. As a low volume trial, I only dyed some swatches and some left over yarn that I had lying around. In my previous entry I covered the basics of indigo dyeing, look it up here if you’re interested.
From the left it’s wool, silk, wool, wool, store bought yellow wool and grey wool. Everything turned out pretty uneven but it’s not realistic to expect perfect result on the first attempt. Besides, it’s indigo, you can always re-dye it for a more evenly dyed fibre.
Considering the instructions for indigo batches I always use Sandström and Sisefsky (1970) for this purpose. Since I don’t know the exact chemistry behind this process (!) I use a linear model to keep the same ratio in each batch. That is, I just multiply or divide the value in the existing instructions to fit the fixed variable. The fixed variable differs from time to time, sometimes I have a finite amount of indigo, sometimes I have a certain amount of yarn I want to dye and sometimes there is a volume limit on the cauldron I am using. This makes me re-calculate everything before dyeing but that’s not a bad thing because I like to have time to think things through, which is something that I am forced to do in such cases.
As you can see, I try to write down the date, mark the fixed variable and then write down the other amounts used so that I would be able to re-do the exact same thing if needed. In that way, it’s easier to say that a certain hue can be made or if I would need to dye some more fabric or yarn in a similar hue.
Concerning the chemistry of the dyeing process, I aim to get a better understanding of the chemistry in time but this is a work in progress. If I am able to do that I think that it is possible to do several process optimisations, which would result in the usage of less material and heat but still having good water and light fastness in the dyed material. Using a linear model is often a very simplified solution, many chemical processes are not well represented by a linear model and it is possible that it’s the same case with the indigo dyeing process. I’ll get back to you if I find anything worth sharing.
The larger piece of wool fabric that you see to the left in the first picture was later on used as a lining for a 14th century womens hood, which is a comfortable use of an uneven dyed fabric since most of it won’t be seen anyway. Tablet-woven edges done using yarn in the same light blue hue from the same batch, just to keep up with the latest reenactment fashion ☆
My hood is made from leftovers so it’s a little lacking at some points but if you want an excellent tutorial for this hood you should check out Katafalks tutorial here.
I still haven’t done anything with most of the yarn since I don’t have any reenactment related ideas, suggestions are welcome. Worst case scenario, it’ll be used for modern knitting.
Smaller batches are always useful for learning and also very easy to handle so I’d definitely recommend it as a good starting point. Developing a habit of writing things down will also make it easier to backtrack your work, to learn from it and to know what kind of colour you will get from a specific setup. Notes are a superior tool in order to communicate methods and results to others; also, you don’t need to remember everything if you have it written down. Overall, information exchange and feedback is fundamental for improvement and to avoid having everyone repeating the same mistakes.
Combine this with a sample set of each batch and you will be on your way to greatness. Now get a fancy notebook and get going.
I’ll try to dig up som old corpses, dyes and crafts that I have done over the years to start with. First out is my very first plant dyed yarn! It was 200 gram of a thick, bone white, single ply wool yarn from Marks & Kattens.
I like thick yarns to naalbind socks and mittens, because it’s quick work and becomes soft, though I have heard that socks made from thicker single plied yarn supposedly gets worn out more easily. I have a pair of socks in this yarn and this has yet not happened to me but maybe I just have baby soft feet incapable of causing harm (not true) or feet sweaty enough to full the wool instead. For example, I can show you how socks made from this yarn has turned into a nice felted sole (if you’re into that kind of thing). But then again, these are just event socks; which means I only use them 1-2 weeks a year so the non existent wear and tear of these socks is not representative of everyday use.
Findings of a single plied sock is yet to be found, I somehow have an idea of it mostly being 2-ply, 3-ply and 4-ply yarn but right now I can’t seem to find anything about this except this small picture on the sock from of the Coppergate findings. If anyone can help me out with a better source on this I would welcome it.
Back to the dye! Done in December 2014, it is the most unregulated and unknown dye I’ve done since it was made from leftovers from a tansy bath that I got from my excellent partner in reenactment crime, Anna (check out her blog!). As such, I have no idea of weight ratio or actually anything about what this was. It could be a mixture of plants for all I know. However, the dye was made with about 2 L of left over bath so I just diluted it with enough water so that the wool could move around and get a even spread of dye in bath. The pot in the picture is a 15 L pot so I’d say that I might have used a ratio of 1:4 of left over dye bath to water; I don’t know why I used such a small amount of water, I should’ve used more but who knows, maybe I was having a bad day…
In the case of dyeing, if your pot is 50L or less, I’d recommend to use as much water as possible. Even though it’s diluted it’s still the same amount of dye just less concentrated (if anyone remembers m [gram] / M [gram/mol] = n [mol] where n is the mole that represents the amount of substance, in this case the amount of dyestuff. Using the formula for concentration c [mol/m3]· V [m3] = n [mol] we can see that n is unchanged since an increase in volume would affect the concentration as well and as such leave the mole unchanged). A larger volume of water is beneficial for the diffusion of the dye bath so that the dye can spread itself evenly through the bath and uneven colouring can be avoided (Dumitrescu et al., 2008; Lewis and Rippon, 2013; Mehrparvar et al., 2016). If possible, I will make a separate blog post where I briefly elaborate further on relevant thermodynamics, diffusion and heat transport.
Anyhow, don’t let confusion get to you just because I used some different words, standardised units and chemical formulas; all of you probably can intuitively come to terms with the idea that more water is needed to give a good flow throughout the yarn and it’s not bad to apply some basic science or analysis in your everyday life. Who knows, it might come in handy later on (the real struggle here is for me to avoid being overly vague or incorrect because if I at some point am, the internet hellhounds will haunt me for the rest of my natural life). Sandström and Sisefsky’s (1975) recommendation on this is a 5 L bath per 100 gram wool which I’d say can be considered a guideline as good as any.
The pre-mordant used was alum, KAl(SO₄)₂·12H₂O but is also known by the name of aluminium potassium sulfate dodecahydrate, used with the generally recommended ratio of 20wt% mordant (Conradi-Engqvist, 1978; Kierstead, 1950; Sandberg and Sisefsky, 1970). Deviations from this recommendation is Vrande (1982) and Råbergh (1978) with 15wt% alum but instead they commonly uses additionally 10wt% tartar or uses post-mordants with a 5wt% of copper sulfate, CuSO4, or iron sulfate, FeSO4, respectively.
It is sometimes considered that older recipes and ratio for pre-, post-, and meta-mordants are overdoing it concerning the recommended amount of mordant; I have not yet done any further testing of different mordant ratios since I only have two pots for dyeing at the moment and as such, I currently consider myself lacking enough equipment to do any good mordant ratio variations. Nevertheless, I think I’d like to give it a go at some point. But yes, I’d be inclined to agree that less mordant can be used but it will affect both the colour and the fastness against water as well as light. Less mordant means less colour intensity and also less wash fastness and less resistance to light. That is, using an insufficient amount of mordant will cause most of the dyestuff to eventually be washed out. Using mordant attaches dyestuff to the fabric due to the complex coordination properties of metals (Lee and Kim, 2004; Uddin, 2014; Mehrparvar et al., 2016), e.g. you can get different hues as well as increased levels of fastness against water and light using mordant (Waheed and Alam, 2004; Burkinshaw and Kumar, 2009; Dumitrescu et al., 2008).So, again, it all depends on what you want. If you want a dyed material with a well defined colour that should be relatively unaffected by both sunlight and washing, it would be suitable to use mordants. Nevertheless, it is also good to use resources sparingly and using too much mordant of any kind is a waste, the question is; how much is too much? What’s the smallest amount that can be used and still get an effect?
Anyhow, enough mordant talk for now, I will have to get back to that subject later.
I don’t have any notes from this dyeing but I think the pre-mordant was done for 60 min at ~90°C and then leave the wool in the mordant bath until cooled. Then I let it hang for a day or two to dry before it was time for the tansy bath. Same procedure with the tansy bath, 60 min at~90°C, let the wool cool in the dye bath.
Despite not having any exact knowledge of what I was doing it turned out Very Nice.
Considering the colour intensity of the yarn, I could’ve probably used the bath for several more dyes but for I had no further dyes planned so I didn’t. The plot twist of this story is that the yarn was supposed to be for my friend in Stockholm but the package was lost or stolen from the letterbox during the christmas holidays. I mourned for a couple of months but I still have a small piece left that I took for reference.
Anyhow, this is so far the most tragic tale I have in the art of plant dyeing so stay tuned for happy excitement as we prod at the dyes of the past.
Conradi-Engqvist, Cecilia (1978). Spinna, växtfärga och forma av tråd: från naturfiber till textil. Spinna ull och lin och forma av tråd : med färg- och kompositionsövningar : studieplan. Stockholm: LT
Kierstead, S.P. 1950, Natural dyes, , United States.
Lee, Y. & Kim, H. (2004), Dyeing properties and colour fastness of cotton and silk fabrics dyed with Cassia tora L. extract, KOREAN FIBER SOCIETY, SEOUL.
Lewis, D.M., Rippon, J.A. & Ebook Central (e-book collection) 2013, The coloration of wool and other keratin fibres: edited by David M. Lewis, Department of Colour Science, University of Leeds, UK and John A. Rippon, CSIRO Materials Science and Engineering, Australia, Wiley, Chichester, West Sussex.
Mehrparvar, L., Safapour, S., Sadeghi-Kiakhani, M. & Gharanjig, K. 2016, “A cleaner and eco-benign process for wool dyeing with madder, Rubia tinctorum L., root natural dye”, International Journal of Environmental Science and Technology, vol. 13, no. 11, pp. 2569-2578.
Råbergh, Hilkka (1978). Färga garn och tyg: växtfärgning, syntetfärgning på bomull-batik, syntetfärgning på ull. Västerås: Ica bokförl.