Isabella Whitworth

probably more than natural and synthetic dyes, wax, resists, and history


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Tyrian Purple – from a Leeds archive?

In early 2008 a small hand-labelled envelope fell from the hinges of a rusty trunk. In it were two knotted twists of purple-dyed threads.

A co-authored paper I’ve written with Professor Zvi Koren about these extraordinary threads was finally published yesterday, after several years’ research. Their existence offers a fascinating insight into the scientific connections and achievements of the people of nineteenth and twentieth century Leeds. You can read the abstract of the paper here

threads_edited-1

I will write more about it in a week or so. If you can’t wait to read the paper, there is a limited number of free downloads available. If you want one, contact me through this website or on Twitter, and I can send a link.

tyrian

Until I am back with more, here are some thanks

To Ambix for publishing our work and for the exceptional quality of their editing

To Professor Koren who set out on this purple adventure with me after a chance conversation at La Rochelle during ISEND

To the owner of the Leeds archive, who allowed us to analyse the threads and the ink on the envelope

Links

Professor Zvi Koren is the Director of the Edelstein Center for the Analysis of Ancient Artifacts at the Shenkar College of Engineering, Design and Art, Ramat-Gan, Israel.

Ambix published by Taylor & Francis Online

Some background to the research already on this blog here

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Celebrating Ethel Mairet

 

submisson

Silk yarn skeins showing the results using two Mairet recipes. The lower skein was divided into three to demonstrate increments of iron added to the vat. Dried cochineal is shown at the lower left

A book of dye recipes by weaver Ethel Mairet was first published in Ditchling, Sussex, in 1916. Its title is Vegetable Dyes. Ditchling Museum of Art and Craft is undertaking a collaborative project to re-interpret and recreate Mairet’s recipes, with the help of  contemporary dyers. There is a considerably large number to complete.

However, not all Mairet’s recipes are safe by today’s standards. Some use toxic chemicals once common in historic use, such as chrome, tin, sulphuric acid, quicklime, lead and zinc and these recipes are excluded from the project, or some individual ingredients amended. Environmental considerations have changed over the years and it is no longer recommended (or permitted) to dye with certain plant material. Lichen dyes, for instance, appear in the book but are omitted from the project because they are rare in many areas and some species are protected. Lichen recipes will be dyed, but by one specialist in Scotland. I am happy with this decision: those who have read my blog for a while know my feelings about dyeing with lichens.

The project is open to natural dyers who are confident handling their materials and they can ‘apply’ for recipes as I did, through the Museum website. The Museum sends material to be dyed; the dyer supplies dyestuff.

The Book 

In Douglas Pepler’s Introduction he quotes the opening lines of the Gospel of St John (In the Beginning..) to illustrate his belief in the ‘goodness’ inherent in discoveries which mankind achieves for the first time. In tracing the subsequent destruction of quality through an urge for quantity (and one assumes, profit), he remarks that this inherent ‘goodness’ is lost. This was true, he suggests, when natural dyes were supplanted by those synthesised by chemists.

In a similar vein Ethel Mairet writes:

‘Dyeing is an art; the moment science dominates it is is an art no longer, and the craftsmen must go back to the time before science touched it, and begin all over again.’

The book is available online.

recipes

The two recipes I selected from Mairet’s book. They are for wool, but I chose the silk option offered by the project

Decisions

 I selected two cochineal recipes to dye onto silk yarn and ‘ordered’ them online from Ditchling Museum. The original recipes were for wool, but the project organisers offered the silk option and I chose it in preference to wool.  One recipe (7, above) uses iron to give a purple shade. (Note that cochineal is an insect, not a vegetable dye, but is included in Mairet’s book).

Many recipes which Mairet collected from the 17th C onwards, before science touched them, are scant on explanation and assume prior knowledge. Compare them, for example, to a contemporary book where a recipe can occupy a page of explanations and options.

So, following the two recipes wasn’t straightforward and often puzzling. I would never in normal practice add wool or silk to a boiling vat. So how should I interpret ‘Boil and enter wool while boiling, till the required colour is got.’?  And should I rinse after mordanting in recipe 4, or sling the cochineal and cream of tartar straight into the mordant as is suggested by the word ‘add? In recipe 7, what colour is considered violet? What does a 1 oz solution of iron mean? And so on. I had to make some of it up as I went along.

Happily, I had no spectators when calculating the Mairet quantities to simple percentages.

I’m including my recipe reports under the links, below. They are not of interest to everyone but indicate some quandaries faced when using historic recipes.


Links

Get involved in the dye project here

Download Ethel Mairet’s book here

Here My earlier blog about Mairet’s madder recipes

Here My blog on dyeing with lichens

Hilary Douglas Clark Pepler

Ditchling Museum of Art and Craft


 

Recipe report page 93, recipe 4: silk

PINK WITH COCHINEAL FOR WOOL

 12 gram silk skein supplied

Calculations were made at

10.4% alum

6% cochineal

12% cream of tartar

Method:

Cochineal ground finely in pestle and mortar.

Silk was washed, rinsed, and remained wetted out.

Mordanting was started cold so that the silk would not be entered at boiling point as the recipe requested (unwise for silk) but was raised to boiling over the period of an hour. It was held at boiling point for 50 minutes.

It would normally be my practice to allow the silk to cool in the mordant and rinse, but the recipe seemed specific about procedure as follows:

Then add 1lb. Cochineal and 5lbs cream of tartar

So I kept the silk in the very hot mordant liquid and added the cochineal and cream of tartar. The colour seemed to ‘take’ immediately and after half an hour the vat looked to be exhausted. The recipe suggests that items be left in the vat till the required colour is got . To obtain a lighter pink, this would have meant removing the yarn after a very short time in the vat which as far as I’m concerned isn’t very good practice. So, using this recipe, a lighter pink would be best obtained by reducing the percentage of dyestuff.

The colour in the sample therefore reflects the 6% of cochineal used.


 

Recipe report page 94, recipe 7: silk

VIOLET FOR WOOL

12 gram silk skein supplied

The following quantities used:

1.5 gr alum

.75 gr cochineal

Iron water as described below

Method:

Cochineal was ground finely in pestle and mortar. Silk was washed, rinsed, and remained wetted out.

No method was given for mordanting in the recipe. Mordanting was started cold and the vat raised to boiling over the period of an hour. It was held at boiling point for 50 minutes, as in my sample for the p. 93 recipe 4 sample. However, for this recipe I allowed the silk to cool in the mordant for several hours and then rinsed it. This is because the recipe seemed to separate the mordant and dye processes, unlike the p. 93 recipe.

Because there was no specific mention of cream of tartar in this recipe (and there was on p. 93), I did not use it in the mordant.

A clean vat was made with cold water and the cochineal added. The silk was entered into the vat and stirred: the colour ‘took’ quickly. The recipe states that the cochineal and iron should be added at the same time but I was reluctant to do this because I do not use ferrous sulphate. Instead I keep a jar of iron water, made with rusty nails, water and vinegar. This serves my dyeing purposes well but means that for this project I could not calculate what the recipe’s 1 oz solution of iron would represent in terms of iron water. I was therefore wary of adding too much too soon.

I therefore dyed the silk yarn for a full half hour, and the vat was exhausted. I added 1 ml iron water to the vat and after ten minutes there was an appreciable change in colour so I removed the yarn.

When the yarn had dried I decided it wasn’t ‘violet’ – or at least not violet enough. So I divided the skein into three equal parts, keeping the original colour as Skein 1. Skein 2 was wetted out, reintroduced into the vat with a further 1 ml iron water, and removed after ten minutes. Skein 3 was wetted out, and reintroduced into the vat with a further 2 mls iron water.

All skeins washed and rinsed to remove iron.

NOTE: The colour of the dyed silk prior to the addition of the iron was almost identical to the sample obtained for p. 93. The two sets of samples thus offer a good progression from pink through to violet and purple.

 Cochineal source The cochineal was sourced from Lanzarote.


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Teaching News

raindrops

Wax resist and steam-fixed dyed scarf. Silk crêpe de Chine. Isabella Whitworth, 2016

I’ve just unpacked after teaching three one-day courses in Oxfordshire. This completes my teaching programme for the year. I teach regularly at only two venues: Ardington, south of Oxford, and West Dean, just north of Chichester.

Ardington School of Crafts is non-residential. My courses there are always one-day, although sometimes linked so that students studying, say, natural dyes can take a further course focusing on indigo. They are suitable for complete beginners. Ardington’s 2017 programme will shortly go ‘live’, and the six dates are on my teaching page here. There will be a variety of courses, all of them repeating popular subjects.

West Dean College is residential, although some students make their own accommodation arrangements. Courses stretch across a few days, have up to now taught resist techniques using synthetic dyes on silk, and have been for beginners and intermediate students.

Many students have attended several of my courses and have progressed very well. After discussions with the Short Course Organiser at West Dean, we have added a new course which will take place from July 20th – 23rd 2017*. Its title will be Handpainted Silk Scarves: Developing Design, Building Technique. This course is designed for those who have relevant experience gained with me or other tutors, but would like to study or practise techniques and ideas not viable on beginner / intermediate courses. Some of the focus will be on design and planning. The idea is to offer more experienced students a course of their own.

However, all students, of whatever experience or ability, continue to be welcome on my beginner / intermediate courses. Although I may be instructing beginners too, more experienced students know they can progress at their own pace within the structure of the course and I can assist them in new directions.

  • My apologies if you read this some weeks ago because I had entered the Advanced Course date in error. The April dates 24th – 27th  are for the Beginners’ Course. The more Advanced / experienced course will be in July, as above.

vat

Inside a vat made from Japanese indigo (Persicaria tinctoria)

West Dean Summer School takes place over three weeks with a separate set of courses each week. I will be teaching a six-day Summer School course from August 5th – 12th 2017 titled Creative Dyeing for Scarves and Fabric. This course will be suitable for beginners, intermediate students and anyone who has studied with me before. My idea for Summer School is to broaden understanding of resist techniques, such as shibori and wax resist, by exploring some relationships between traditional and contemporary dyeing. The course will feature a natural indigo vat which can be used as well as (but not together with!) synthetic dyes. Indigo has a unique and beautiful affinity with resist techniques, and many contemporary resist processes are based on its traditional use. There will also be opportunities to discuss and develop designs for wax resist work. More details will appear on the West Dean website.

Teachers and technicians can apply for a 50% discount on a Summer School. Contact West Dean on 01243 818300 to register your interest, with the name of your school, college or university, and a 1st, 2nd and 3rd choice of Summer School course. 

Booking for 2017 is now open via West Dean (link below). 

My February 2017 course is full.

Links:

Ardington School of Crafts

West Dean College


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Mordant Pastes 2

Recently I wrote about experimental work I’ve been doing with a colleague, using mordant pastes. See here to read the post. I recently completed a batch of work using the pastes and combining them with wax resist. All work is on silk crêpe de Chine.

 


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Testing Times 1 & 2

Testing One

I have many friends who take an interest in my pots of goo and occasionally they send me things. One such friend returning from Essaouira sent me pigment she had been sold as ‘shellfish purple’. Historically, the Moroccan coast was an area much involved in the making of this fabled dye (also known as Imperial Purple and Tyrian Purple) but I expressed doubt that what she had sent was ‘the real thing’ because it is fabulously expensive to produce even a small quantity. Just 5 grams costs around £450.00. But I thought it would be fun to try dyeing with it.

grains

Green grains and finished colour on silk

I took advice from a specialist colleague, Professor Zvi Koren of the Edelstein Center for the Analysis of Ancient Artefacts (link below). He advised that shellfish pigment is not water-soluble, so that by adding just water I would not get a true solution: I’d get a reddish coloured mixture with the pigments dispersed but not dissolved. I added water and the grains went bright pink. Very bright indeed, as you can see below.

pH

The colour of the grains in solution: testing pH

reduced

Reduced liquid with lumps of dye matter

Following my colleague’s advice, I reduced grains in a hydrosulfite / dithionite bath in an alkaline solution, at about 60 C. The liquid went completely clear, with the dye matter gathered in lumps. This didn’t look right at all for shellfish purple, which should change to a greenish colour (as with indigo).  Nevertheless, I dipped silk into the clear mixture and it came out a bright pink – which does not wash out. So it’s certainly a dye, but certainly not shellfish purple.

Two other pointers to its not being shellfish purple: the Essaouira grains are green, and they shouldn’t be. There’s no snail pigment that colour, according to my colleague. It’s usually dark, blackish, brownish, purplish or violetish, but never green. And on top of that, the grains should have a yukky fishy smell. The Essaouira grains smelled vaguely of incense.

So this was a fascinating experiment, a story echoing many historical tales of dyes that were not as they claimed.

My thanks to Professor Zvi Koren of the Edelstein Center for the Analysis of Ancient Artifacts for his input and advice on testing the Essaouira grains.

Friends: please don’t stop sending me interesting things. But as an H&S caveat, pigments and grains bought in faraway places may be toxic or otherwise harmful so you need to be aware of handling and storing them. They are not necessarily what they say on the tin.

Testing the Other

At a recent course at West Dean my Old Geyser of a fabric steamer developed a problem. The thirty-year old steamer assembly consists of a standard water boiler (the sort to be found in every village hall), a custom-made stainless steel chamber, lid, and perforated base plate. Silks are rolled in paper and stacked upright inside the steel chamber. Water is heated in the boiler, the steam circulates and the combination of heat and damp sets the dyes. The water isn’t held at a constant boil but needs to come up to the boil – and hold it – every two or three minutes, for around two-and-a-half hours.

Only, at West Dean, it didn’t. The boil was less frequent than usual, and was held for shorter periods. I was concerned that dyes were insufficiently fixed and suspected a problem with the thermostat. (I should add that West Dean supply a professional Uhlig steamer, but I have always used mine, which holds more silk).

Back home, phone calls revealed that a new ‘simmerstat’ is what I required. But during the time since I bought the boiler, Brussels has dictated that EU citizens are insufficiently responsible to handle dangerous pieces of equipment that boil water. (Those in favour of Brexit might enjoy the link at the bottom of the page). A catering boiler will no longer come to a full, constant boil. My new simmerstat was fitted by the technical department, but the gaps between boils seemed longer than I remembered…. or was I just being twitchy?

I then discovered that a secondhand Uhlig steamer was on sale, owned by an ex-student. I couldn’t believe this piece of luck – and bought it. It is a solid, stable and well designed piece of equipment, although as with the West Dean one, it does not hold as much yardage as Old Geyser. In the Uhlig I tested several pieces of silk, including three blues which have a tendency to run if steamed sufficiently. No run-off.

runoff

Some runoff may be expected in initial rinses after steaming if heavily concentrated dye is used. Thereafter the water should run clear

samplessteam

Samples of identically dyed silks steamed in two steamers to compare colour and runoff

I tested identical blues in the mended Old Geyser. It now appears to be working well too – so I now have two working steamers. No recycling tip for Old Geyser: he threw a steamy party.

LINKS

Where to buy shellfish purple in 2016? Here

Brexit? Pulling the plug on high speed kettles here

The Edelstein Center for the Analysis of Ancient Artifacts here

 

 


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Mordant pastes

The work I’m briefly describing here is an offshoot from a joint project. I have been researching mordant pastes (as taught by Michel Garcia) with a dyer friend; eventually we will write up our work because it isn’t yet finished. But the work we have done has made me wonder if it wasn’t the key to finding a satisfying, creative way to use natural dyes in combination with wax resist. This has been an ambition of mine since I went to ISEND* in 2011. It’s there I first came across Michel Garcia, on whose generously-shared research our mordant paste work is based.

There are technical problems in trying to combine paste with wax resist. Wax melts in the vat if it’s taken above a certain temperature, and each dye needs at least some heat to fix it. Cold dyeing isn’t an option: it would all take too long. The dyes must take their place in an ordered sequence for colour. The pH of one vat can affect colour of dyes in another layer, the wax can begin to flake off, etc. If the indigo dips are included, there may be as many as 20 operations to create one scarf, as they did in the image below. So it’s time consuming and isn’t going to produce a low-cost item, but I feel I’m getting somewhere at last. The dyes used are weld (Reseda luteola) from a British source, and indigo (a mixture of Devon-grown Persicaria tinctoria and imported powder from Tamil Nadu). The different paste resists give different shades of yellow on the base layer, including the brownish colour visible in small, thin lines and spots which came from the iron in the mordant paste.

Follow up post in July 2016: see here.

pastes

Mordant pastes (iron, alum and titanium) on silk crêpe de Chine. Weld immersion-dyed; wax resist, indigo-dyed, wax resist and multiple indigo dips

* ISEND: International Symposium and Exhibition on Natural Dyes, La Rochelle, 2011. You can download information about this here

A little about Michel Garcia’s technique here