Wednesday, 26 August 2009

Japanese Indigo

These skeins of yarn (commercial spun, not my spinning) are all dyed with indigo from Japanese Indigo plants (Persicaria Tinctorium) grown at home, on the front room windowsill and in the greenhouse.

The yarns in the top row are a Traub worstead spun wool, in the bottom row spun flamme silk from Gaddum & Gaddum Ltd. (I intend to use these yarns in weaving scarves).

And this is what the plants look like, they are the straggly green leaved plants. The dark leaves belong to basil "Purple Ruffles" and the stoneware pot at the left side of the picture holds a Pelagonium with nutmeg scented leaves.
The seeds arrived in the post last winter from one of my friends in the Online Guild of Weavers Spinners and Dyers, along with instructions for different ways of making dyebaths and some samples from my friend's dyeing.

Following my instructions I found a large Kilner jar, filled it with leaves, covered them with water and left the jar to stand for a few days. The "few days" turned into a week, and the leaves had started to ferment. Gas bubbles pushed the leaves up the jar and it overflowed (note: next time leave a couple of inches empty at top of jar). The liquid at the bottom of the jar looked yellow, and it began to smell like rotting brassicas (i.e. cabbage, another plant in the brassica family).

Even before the dyeing process was begun, it was clear that these leaves contained blue pigment, see what has happened where this leaf is damaged...

Before the dyeing session I also had to prepare the yarns. The wool came in an 100g skein, from which I wound smaller skeins (not weighed, but 12 skeins of differing lengths), and the silk came on a large cone. When the skeins were wound, and loosely tied at least 5 or 6 times per skein, I put them into pans of warm water with detergent and heated them gently for about 20-30 mins. to make sure they were well scoured of any substance (especially lanolin in the wool, seracin in the silk) that might impede dye take-up. After the detergent and anything else was rinsed out, I left them in bowls of water to wait for dyeing.

The dyebath was prepared by warming the jar in a bain marie, created by resting the Kilner jar on the stainless steel basket from my pressure cooker, turned upside down in a 20 litre stainless steel dye bucket.

The instructions said to raise the temperature slowly to 71 degrees centigrade. I actually stopped heating it at 68 degrees. Then, I stained the liquid from the leaves with a nylon sieve that I reserve for dyeing use, poured the liquid into my bucket, and whisked for 20 mins with a slotted stainless steel spoon. At the end of this time the bubbles looked blue.

Why whisk? To introduce air into the liquid and oxidise it (i.e. introduce oxygen). There's a good article about using Indigo in Shibori dyeing in the latest Journal. Author Jane Callender explains how the oxidisation causes two indoxyl molecules (which are unstable) to combine and form the blue pigment indigotin.

The next stage was to add an alkali liquid to the dyebath to adjust the pH level. I was going to use "washing soda", but my dyeing instructions did not tell me how to make the liquid.

I recalled that I have a little booklet from Helen Melvin: "The Colour of Sea & Sky: The Art of Dyeing Indigo". I ran to find it, confident that she would have explained this - and there it was, p.9. 4 tablespoons Soda Ash into a litre of very hot water. Thank you Helen! It was like having a friend on hand when I needed you.

The dyebath was returned to the electric hob and warmed up to 50 degrees, and then half a spoon of "spectralite" sprinkled on the surface. This is a reducing agent (reduction is the removal of oxygen). Jane Callender says " a reducing agent... removes or 'digests' some oxygen from the indigo [and] causes it to change to leuco-indigo". The change is visible to the eye, as the dyebath gains a yellow tone, which took my dyebath from very blue to a deep moss green. Good! Just as my instructions said it should... so, time to add a couple of small wet skeins, and leave them 10-15 mins for the dyebath liquid to penetrate. Helen makes the point that leaving material in an indigo dyebath longer does not give a deeper colour. Deeper colours are produced by re-dipping... I remember reading about this before in Jenny Balfour Paul's book "Indigo" which is a wide ranging account of the historical and worldwide traditions of indigo dyeing.

After several skeins had been dyed, the reduced bath became more yellow, and this very yellow looking bath below was the one that actually gave the deepest shades of blue.

I used almost all the bowls and buckets I could find. I had one bowl with wet skeins of wool ready to dye, another with wet silk ready to dye. I had a bowl to rest my sieve on to put yarn in when it was immediately out of the dyebath...

oh, better interupt here. When the yarn is lifted out of a dyebath, like that one pictured above, it looks yellow. The blue colour forms as the pigment oxidises - or takes up oxygen from the air. Magic to watch!

...back to buckets etc, see below, a bowl to rinse the yarn after it has oxidised and turned blue, then a bucket to soak it a while in a strong saline (salt water) solution. A bowl to leave the saline soaked yarns until I get a moment to rinse them. The rinse and the soak in saline are essential to remove excess pigment and fix the colour so it won't rub off the yarn later.

It was all great fun and I was happily "singing the blues" to myself throughout this wonderful dye session.

(article)Indigo and the Tightening Thread, Jane Callender, in The Journal for Weavers, Spinners and Dyers, 231, Autumn 2009;
The Colour of Sea & Sky: The Art of Indigo Dyeing, Helen Melvin, copyright 2007, self-published;
Indigo, Jenny Balfour Paul, 2nd edition pub. Archetype Publications Ltd. 2006, ISBN 1-904982-15-8


Peg in South Carolina said...

Thank you for sharing this. I doubt that I will ever do indigo dyeing but I really enjoy reading about your process. I can understand why people enjoy working with indigo. And I am so glad you have the energy both to do this AND to write this wonderful blog post!

Meg said...

What an excellent, excellent post, and a lot of work. As a child I remember watching films of Indigo dyers "rinsing" their silks in dye baths - now I know they were oxidizing! I am so very tempted to see if I can get my hands on some indigo seeds, too, Dot!

Helen said...

Fantastic blog -so very clear and well explained.
I haven not tried this method of using the leaves but Enys bought a load around from her greenhouse and and I will try it ready for my next workshop on Saturday. We will pick the fresh ones for turquoise.
I am interested you said you got jade at the last dip.If the pH drops the colour moves towards a greener blue but fresh Persicaria leaves will also give turquoise with acid-I know really confusing!- so I am intrigued at what might be going on.
Many thanks
and it is so good to know you are feeling better enough to do this! :)

Debbie said...

Excellent write up Dot - really clear and interesting. I'm thrilled you used the word indigotin for the name of the dye chemical, although it is the correct terminology so few people use it!!

Great to hear you're so much better!


Lesley said...

Really useful post Dot. Well done! I am inspired to go get some seeds. I imagine there will still be time to plant and get something before winter sets in.

Margreet said...

Dot, I really enjoyed reading about your dyeing blues! I have not tried this method, just used the powdered Indigo and as you say, it is magic when it comes out of the dyebath yellow and turns blue in the air.
Makes me feel like getting some plants to try myself... though I find that using the powdered Indigo, I'm able to dye within hours and get lovely results.
Glad to read that you are getting stronger and able to do things like dyeing again! Thanks for sharing.

Life Looms Large said...

Those are gorgeous colors! I love the picture of the skeins hanging to dry!

Funny that you know what the rotting smell reminds you of....that's a discerning nose!

Interesting that the yarn and bath change color! I would never have guessed that - and it's really good for other dyers that you documented it so well here!


Benita said...

What a fantastic post!!! I have never seen indigo processed from leaf to dyed fiber before and this is fascinating. Okay... I'm am going to grow my own indigo and try this. It look way too cool!

Anonymous said...

Fascinating information -- I have dyed with indigo baths (set up by others) before, but didn't realise it came from a plant. I have fond memories of watching the magical transformation of murkiness into that beautiful, deep blue. I may have to give my black thumb a go at growing this plant. Thank You for the post!

trapunto said...

I love the way the skeins look all lined up to dry, and the blue showing in the damaged leaf. The lighter shades of indigo don't get used much, and they are so pretty.

Joan Murray said...

I saw a show on North Carolina public tv about old time weaving and dying. The old woman was showing how she dyes indigo. she had a big vat outdoors over a wood fire, but the one thing she did differently from your description, was she didn't do the stirring to make the dye blue, after the dye vat was ready, she dipped the wool for a certain time, then pulled the wool out and threw it over a wood rod and shook the wool (to let the air at all the threads) to activate the color, the longer the airing out the darker the color. She would let it air out for 10 minutes then soak in the dye vat again. Of course she was outdoors and it doesn't matter there how much mess is made.
It's a gorgeous color done either way!

charlotte said...

What an extraordinary interresting post! I have never seen/read a description of the whole process from plant to dyed yarn, I have just dyed with synthetic indigo powder. It is deeply fascinating to see your photos of the blue stained leaves, and to read your account of the fermentation process.
Thank you so much for blogging this!

Leigh said...

Great post, and interestingly timely because one of the gals in my guild announced yesterday that her Japanese indigo was ready to harvest and she was inviting folks over to come and dye with her. If she didn't live so far from me I'd have taken her up on it. Even so, I may be able to try some of my own someday. Your info will be very helpful, as will the Journal article.

Anonymous said...

wunderbar, ich habe es auch getestet...und habe mit Waid auch gefärbt..
nun stricke ich gerade und webe mit dem Garn..`s wounderful...your clours..
wiebke from germany..

Barbara Blundell said...

Hi Dorothy ,
What an informative and fascinating account ! And what patience-but well worth all the effort .
Glad you are feeling better.
Were you singing "In My blue Heaven " at the end ?
Look forward to seeing the end products

Anonymous said...

Dot, this is fascinating! I took a semester of painting on fabric many years ago and one class was about dying with indigo. I remember the magic when the fabric was removed from the bath and started turning blue. But I love the fact that you grew the plants yourself and shared the whole process of how to do it. I'm inspired to try it myself. Thank you!


Charlotte said...

This is fascinating! I'd heard about indigo dying but never seen it. Thank you for sharing all the details and good luck with weaving with the skeins.

Angela said...

Hi there, I wonder, do you have a contact where I can purchase seeds in order to grown the plant to produce indigo dye? My daughter has to write an extended essay for her IB and she has chosen to write about Japanese indigo dyeing and it would make perfect sense to try and grow plants and maybe produce a little dye. Thanks in advance.

Dorothy said...

Hi Angela, try P&M Woolcraft, also Wild Colours.