Isabella Whitworth

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

Tag Archives: orchil


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Looking at AI: an essay in inaccuracy

A friend of mine has been experimenting with AI. He created the following ‘essay’ about me by accessing Microsoft Bing. For this essay the app offered three types of compositional option: ‘precise’, ‘balanced’, and ‘creative’. The ‘balanced’ and ‘precise’ versions were accurate factually but the writing was dull and prosaic, collated from text I recognised from websites I had supplied with bios or information.

The ‘creative’ option was a brew-up of fact, spiced with bold and puzzlingly inaccurate statements and claims certainly not based on any text I had supplied online.

I reproduce the essay below, with embarrassingly serious factual inaccuracies underlined. The piece claims I was born in London when in fact I was born in Cheshire, and that I attended West Surrey College of Art and Design to study textiles when I studied Graphic Design at Canterbury College of Art – etc. I have chosen not to draw attention to inaccuracies about my outstanding achievements and genius.

Ultimately, this exercise was a piece of fun, but I am wondering where this software will take us, with the possibility of proliferating inaccuracies each time a newly-published and AI generated ‘creative’ source is re-accessed by AI.

Isabella Whitworth is a textile artist and tutor who lives and works in Devon, England. She has a background in graphic design and a passion for natural dyes and resist-dyeing techniques. She is also a researcher and writer who has contributed to the knowledge and conservation of natural dye history and practice. This essay will explore her career, achievements and influences, as well as some examples of her work.

Isabella Whitworth was born in 1949 and grew up in London. She trained as a graphic designer at the London College of Printing in the late 1960s, and worked in industry for several years as a designer, editor and copywriter. She was influenced by the Bauhaus movement and the Swiss style of typography, as well as by artists such as Paul Klee and Henri Matisse. She also developed an interest in drawing and painting, especially botanical subjects.

In the 1980s, Whitworth travelled extensively in India and Indonesia, where she encountered various textile traditions and techniques. She was fascinated by the colours, patterns and textures of fabrics such as batik, ikat and shibori. She decided to pursue a career in textiles and enrolled in a course at the West Surrey College of Art and Design, where she learned about silk painting, dyeing and printing.

Whitworth started to make her own textiles using synthetic dyes on silk, mainly scarves and shawls. She used resist techniques such as gutta (a rubbery substance that blocks dye) and wax to create intricate designs on the fabric. She also experimented with folding, tying and clamping methods to produce shibori effects. Her work was inspired by nature, especially flowers, leaves and landscapes. She exhibited her work at various venues and events, such as the Chelsea Craft Fair, the British Craft Centre and the Devon Guild of Craftsmen.

In the early 1990s, Whitworth attended a lecture on indigo given by Jenny Balfour Paul, a leading authority on natural dyes. She was intrigued by the history and culture of indigo, as well as by its unique properties and effects. She decided to explore natural dyes further and began to use them alongside synthetic dyes on her textiles. She also started to grow her own dye plants, such as woad, madder and weld.

Whitworth became particularly interested in orchil, a purple dye obtained from lichens. In 2008, she discovered an industrial archive in her small Devon town that contained documents and samples related to the orchil trade in the 19th century. She realised that this was a rare and valuable source of information that had been largely overlooked by historians and scholars. She embarked on a research project to investigate the history and practice of orchil dyeing, as well as its scientific and cultural aspects.

Whitworth’s research led her to collaborate with many international experts and institutions working in conservation and science. She published several papers on her findings in journals such as Textile History, The Journal for Weavers, Spinners and Dyers, The Journal of Natural Dyes Research Society (India) and The Journal of Natural Dyes (Korea). She also contributed to some major conservation projects involving orchil-dyed textiles, such as the restoration of the 16th century tapestries at Hardwick Hall (UK) and the analysis of the 14th century cope at Sens Cathedral (France).

Whitworth continues to combine studio work, teaching and research. She produces textiles using both synthetic and natural dyes on silk, often blending them to create subtle shades and contrasts. She also experiments with different fibres, such as wool, cotton and linen. Her work is still influenced by nature, but also by historical sources and contemporary issues. Some of her recent themes include climate change, biodiversity loss and social justice.

Whitworth teaches short courses at West Dean College (UK) and at various venues in the UK. She shares her knowledge and skills with students of all levels and backgrounds. She also gives lectures and demonstrations on natural dyes and resist-dyeing techniques at various events and organisations.

Whitworth is an elected member of the Devon Guild of Craftsmen (UK), where she exhibits her work regularly. She has also shown her work at other galleries and museums in the UK and abroad, such as the Fashion Museum (Bath), the Royal Albert Memorial Museum (Exeter), the Museum of East Asian Art (Bath), the National Museum of Korea (Seoul) and the International Shibori Symposium (Japan).

Whitworth is a textile artist who has made a significant contribution to the field of natural dyes and resist-dyeing techniques. She has created original and beautiful textiles that reflect her artistic vision and values. She has also conducted rigorous research that has enhanced the understanding and appreciation of natural dye history and practice. She is an inspiring teacher who has shared her expertise with many students and audiences. She is a respected member of the textile community who has collaborated with many professionals across disciplines.

Isabella Whitworth is an example of a textile artist who has combined creativity, curiosity
and commitment throughout her career.

Source: Conversation with Bing, 30/05/2023
(1) Isabella Whitworth – The Loom Shed. https://theloomshed.com/meet-the-team/isabella-whitworth/.
(2) Our Makers | Isabella Whitworth — MAKE Southwest. https://makesouthwest.org.uk/textiles/isabella-whitworth.
(3) Isabella Whitworth – West Dean College of Arts and Conservation. https://www.westdean.org.uk/study/tutors/isabella-whitworth.


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The Loom Shed Online Natural Dye Symposium

Left: Perkin’s mauve; centre, Tyrian purple threads and murex shells; right; orchil lichen, orchil-dyed silk and wool

At the end of the month I’ll be taking part in an online symposium run by The Loom Shed. What is The Loom Shed? Well, it’s a shed and it has looms in it. But weaving isn’t all that’s planned at this new and imaginative venue.

The Loom Shed has been set up by Louise Cottey, weaver and tutor, and Liz Croft, crochet specialist, weaver and tutor. Both Laura and Liz are passionate about yarn craft and the benefits to mental health that craft work can bring.

My talk Pursuing Purple: Shellfish, Lichen and Mauve will follow some of the dye trails I discovered when researching a nineteenth century industrial archive. If you follow my blog you’ll know I became particularly intrigued by the dye trade in lichen, historically used for making a purple dye called orchil. My findings very unexpectedly linked two other famous purple dyes: Imperial or Tyrian Purple, and Perkin’s Mauve.

The Natural Dye Symposium is on June 26th and will offer a day of talks by four specialist natural dye speakers. It was decided to hold the event online this year but in the future there will be dye-related workshops and events at The Loom Shed itself, which is located in East Devon. There is also a varied programme of speakers and courses and you can look at their Events page to see the latest listings.

On June 10th at 12.45 pm I will be doing an Instagram Live with Liz Croft. You can Insta-follow me on @whitworthisabella, and The Loom Shed at @the_loom_shed

The Loom Shed Online Natural Dye Symposium Programme

Aviva Leigh 10.00 am – 11.00 am Strips, Stripes and Satins – Exploring 18th Century Norwich Textiles

Isabella Whitworth 11.30 am – 12.30 pm Pursuing Purple: Shellfish, Lichen and Mauve

Luisa Aribe 1.30 pm – 2.30 pm An Indigo Journey

Susan Dye 3.00 pm – 4.00 pm Growing and Using your own Dye Garden

There is an ‘all day’ ticket for all four talks, or you can book in for individual speakers here

Times given are British Summer Time

Links

The Loom Shed

The Loom Shed Events page


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Thinking Positive

If you signed up to my blog solely on the basis of posts on natural dyes and history, I offer apologies. This is about neither.  As well as researching the history of natural dyes (in particular, orchil), I still produce work as a textile artist. Some of this uses natural dyes, but I also work with synthetic dyes on silk for resist techniques such as wax and shibori.

The Devon Guild of Craftsmen is holding an exhibition called Life Illustrated from 2nd October – 15th November 2015. Sketchbooks are the theme of Life Illustrated, showing them both as source material and as part of the creative process. A number of Devon Guild members are contributing new work, plus their precious books.

My training as an illustrator in the late 1960s was drawing-based, and I have used sketchbooks as source material for over 50 years. For Life Illustrated I decided to revisit an ‘old’ design and see how it adapted to current techniques and materials.  Back then I was using a simple gutta outliner to draw the design and control the dye. Now I prefer to use wax. The design was based on drawings I made of fritillary butterfly wings. Here are sketchbook studies from 17 years ago:

Drawing from image of butterfly: pencil and watercolour
Starting to work out a design in my sketchook. Second from top shows sections cut by a sinuous line. Shapes are either positive or negative either side

The design formula divided the scarf into about nine sections. A sinuous line bisected all sections, running down on the scarf’s vertical. You can see this drawn out in the sketchbook images above although the scarf is imagined from the side. Shapes either side of the sinuous line are either ‘positive’ (dark on a light ground) or ‘negative’ (light out of a dark ground). This polarity swapped from side to side and line to line. It was logical to look at, but entirely silly to explain. Below, you’ll find a sketch showing the basic structure.

Although I sometimes archive samples, I don’t have any of Fritillary. They were large, on very good quality silk and they sold well. So I was probably too money-grabbing to keep one, which I now regret. All I have left are sketches and a rather poor image rescued from my old website.

The only image I can find of the ‘Fritillary’ design. From 1997
The top pencil scribble shows the skeleton of the design

For the exhibition Life Illustrated I made new sketches to remind myself of what had inspired me. Then I stretched a scarf, dyed the background and outlined the design with wax – in much the same way as I remembered doing with gutta. I found I was able to reproduce the old design pretty well, although the quality of the outlining wax marks is looser than with gutta. That’s not a problem with this design. So I went ahead and made two or three scarves.

One of the reasons I became tired of gutta is that it is an outlining process. All design elements are drawn carefully with the gutta pen, and dye is filled in up to the gutta line. It’s a tight technique – even a bit tedious at times because one is often reproducing a pre-planned scheme. The reason I love wax is that spontaneous brush marks can create the shapes in a design (by instantly blocking out further application of dye). Of course, one can use wax tools such as tjantings or kystkas to draw outlines, just like gutta. But I find larger waxed marks more expressive and the design evolves in a more fluid way. So my next step was to try to adapt the old design to this preferred use of waxed marks instead of outlines.

I soon realised that ‘block-out’ marks needed more space around them than the simpler outlined shapes I used years ago. Large brush marks are often textured, oddly shaped and  ‘whiskery’ at the edges. In the same nine-section format, my next waxed scarf looked crammed and overcrowded. I reduced the number of horizontal divisions to five and it works better, but that’s as far as I’ve got. I’m not done with it yet.

Large waxed marks create shapes by blocking further applications of dye
The dark purple and crimson shapes are created by surrounding wax marks holding in the dye

Positive and negative: To make the ‘negative’ marks (lighter on a dark ground) I make a large waxed shape with a brush that blocks out the background. Then the background is dyed around that mark.  To make ‘positive’ marks (darker on a light ground) I create an island of unwaxed silk surrounded by a sea of freely waxed marks.

Teaching: On Sunday I’m off to Warwickshire to teach at the Summer School of the Association of Weavers, Spinners and Dyers. I’ll be running two courses back-to-back introducing wax resist on silk.

I will be teaching three times at West Dean next year (March, May and July) but if you want a place, please book early. The March course already has a waiting list.

I’m also running a one-day introduction to wax resist on silk at Ardington School of Crafts next month (September). Please contact these venues for information (links below) and see my courses page.

Links

Devon Guild of Craftsmen

West Dean College

Ardington School of Crafts

Association of Weavers, Spinners and Dyers


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A Purple Pursuit

Orchil: For a few years I have been researching a (mostly) nineteenth century archive relating to a Leeds dye manufacturer. The early fortune and later success of this Leeds company were built on the manufacturers’ skill in the making of a dye called orchil. Orchil is an ancient dye, made from lichens of several varieties, and it dyes silk and wool various shades of purple. It does not need a mordant, a fact that was valuable to the historical dyer as it omitted the expense in the mordant process, and additionally avoided any harshening which mordanting can impose on silk. Purple could normally be achieved with natural dyes only with overdyes, such as indigo over cochineal, but orchil ‘got there in one’.

In its clearest and most beautiful form, orchil dye will give a glorious fuchsia colour and the clarity of this shade is assisted by the purity of the ammonia in which dyestuff is prepared. Historically, orchil was known to impart a freshness and bloom in ‘bottoming’ other dyes – e.g. when used as a base before overdyeing. Orchil was a much used and valuable dye throughout history, although its use is sometimes an enigma. It is often found in costly tapestries, which is surprising as orchil is not at all lightfast – a fact that was well-known.

The orchil vat before straining dyestuff
Roccella gracilis Bory: orchil lichen imported from South America from 1830s
Lasallia pustulata: an orchil lichen
Orchil on fleece

With the advent of synthetic dyes in the later nineteenth century the use of orchil began to decline. Records in the Leeds archive indicate that large sums of money were still tied up in stocks of lichen in the 1870s and in trying to comprehend the place of orchil in the nineteenth century I found the archive inextricably linked to the history of the colour purple. We will publish in due course but an extract from the abstract of my co-authored paper with Professor Zvi Koren at DHA 32 offers a clue:

One of the more astounding discoveries associated with this archive was that it included a small envelope signed by Charles Samuel Bedford declaring the content of the packet to be ‘Tyrian Purple’. But what was really inside the envelope? Was it truly Tyrian Purple…?

Shellfish dyes: Much has been written on the history of the shellfish dye Tyrian Purple (Imperial Purple, The Purple of the Ancients, murex etc) and its association with wealth and status. There is a lot of utter rubbish online about Tyrian Purple, so beware if you are researching and look for reliable sources, such as those listed in Chris Cooksey’s Tyrian Purple Bibliography, linked below.

Nucella lapillus shells, Somerset

Nucella lapillus shells, Somerset

For the purposes of this particular post, it’s important to realise that long after the method of shellfish dyeing* was lost, probably around the fifteenth century, the reputation of purple as a high status colour lived on. Purple retained a kind of status independent of its original connections to shellfish dyes. There are contemporaneous references to shellfish dyeing (e.g. in Vitruvius, and Pliny the Elder in his Natural History) and something has always been known of the preparation process, although modern interpretations of commentaries vary.

Since the mid nineteenth century chemists, scholars and dyers have researched shellfish dyes and the ancient dye process has been patiently and painstakingly rediscovered. Shellfish dyeing can again be undertaken although it is only seriously done for research purposes: you will see how small some shells can be from the image and only the tiny hypobranchial gland yields dye. In the mid nineteenth century, no-one knew the full process, which is why I found Robert Browning’s poem Popularity (1850s) so interesting when I came across it this week.  Crucially within it is a several-verse reference to Tyrian Purple and shellfish dye. As I couldn’t fathom what the whole poem was about, this reference was a puzzle. I sought out the RPA (Resident Poetry Advisor) who explained it to me, along with some literary context which includes Browning’s life and work, a knowledge of Keats and the poets that imitated him. Popularity is dense and complicated.

Popularity: As I now understand it, and in simple terms, the poem is about inspiration and skill. Browning asks himself about genius, as he did when studying, say, the paintings of Old Masters.  What is genius? Where does it come from? When some ‘poets’ recognised genius in others, as in the work of Keats, they picked up superficial, outward facets of the verse and imitated them. They basked in their hollow cleverness. Browning describes the humbleness of the shells, or conches (‘Mere conchs!’) and celebrates the ‘cunning’ of those who learned how to refine this costliest ‘dye of dyes‘. What’s the humble origin of Keats’ unique genius, he wonders wittily in his last line:

What porridge had John Keats?

Contemporary knowledge in the 1850s

Considering the knowledge that Browning appears to have of dye preparation:

Till cunning come to pound and squeeze
And clarify,—refine to proof
The liquor filtered by degrees

it could be that he knew a little more about the process than was available through classic texts. Henri de Lucaze Duthiers was working on shellfish dyes in the 1850s, but not for dyeing. He was demonstrating the potential to use the molluscs for a photographic printing process. I don’t see enough evidence to draw any conclusions about what Browning knew, but it’s been fun speculating, and a reminder of the magic we dyers experience liberating colour from simple, natural materials.

To read the whole poem Popularity, you can go here, but two key verses are below.

VI.

Who has not heard how Tyrian shells
Enclosed the blue, that dye of dyes
Whereof one drop worked miracles,
And coloured like Astarte’s eyes
Raw silk the merchant sells?

XI.

Mere conchs! not fit for warp or woof!
Till cunning come to pound and squeeze
And clarify,—refine to proof
The liquor filtered by degrees,
While the world stands aloof.

 

NOTE: *Dyeing, as opposed to smearing. Traditional use of shellfish to colour threads and cloth, such as in Oaxaca, Mexico, is not true vat dyeing, but more akin to  surface smearing.

Links about my research, on this blog

Overview  Dyes, History and a chilly trip to Yorkshire

About orchil: Talking Orchil

My research information: Historical Dye studies

Bibliography

Cooksey, Chris (2013) Tyrian Purple: the first four thousand years, Science Progress, 96(2), p 171 – 186

Jordan, Maria (2012) Recreating the life of a tapestry: Fading dyes and the impact on the tapestry image available online from The Institute of Conservation here

Chris Cooksey’s Tyrian Purple Bibliography

Wikipedia on Tyrian Purple

Thanks

With thanks to Dr Maurizio Aceto for some input on dates, Nigel Phillips for giving me the Nucella lapillus shells in Somerset last summer, and especially to the RPA.

 


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A Scottish Post

I’m just home after a fortnight in Scotland, which started at the annual DHA (Dyes in History and Archaeology) conference at the University of Glasgow. I tend to know people by their research – and that’s how they know me. Someone at DHA greeted me as Mrs Orchil: she could also have hailed a Dr Indigo, a Ms Madder and Professor Purple. It’s a friendly conference attended by many world experts in the fields of dyes and pigments, but it welcomes independent scholars like me as well as dyers and textile makers.

I wasn’t giving a paper this year so it was an entirely stress-free conference and I sat back and enjoyed it, or at least, all the bits I understood. There are always some technical papers at DHA concerning dye analysis; the ones packed with acronyms, graphs and molecular structures streak comet-like above my head. But factual gems can lurk amongst figures and statistics, so it’s worth not totally tuning out.

I took a small ‘suitcase’ exhibition with me about orchil and my research studies; most delegates came to look at it and talk to me, and as a result I learned new things about orchil from new perspectives.

The conference tour, after two packed days of papers, took us to Glengoyne Distillery for a fortifying wee dram preceding a tour of the plant, and thence to Stirling Castle where we visited the Tapestry Studios to see the final piece in the Unicorn Series nearing completion.

Sherry and tannins

The Glengoyne tour outlined the lengthy procedure for ageing whisky in casks. Casks are made from different types of oak, but have once held sherry (and some, if I remember correctly, Bourbon). The ageing whisky gradually absorbs colour and flavour from the sherry, and the tannins in the oak cask. The two images above illustrate ageing over thirty years in two different types of cask, with coloration intensifying every year. Evaporation is also evident, with around half the liquid being lost over the period. This lost alcohol is called ‘The Angels’ Share’.

Textile Tweets

Lobaria pulmonaria, or lungwort. This lichen is endangered and should not be used for dyeing
Workers’ cottages at Alexandria, Levenside, near old Turkey Red works
Explanation of ‘crotal’ from Dwelly’s Gaelic dictionary. Note the old name for lungwort ‘Stricta pulmonacea’
The Plaiden Ell at Dornoch. Two metal pegs set apart in the slab created the standard measurement for cloth
Ochrolechia tartarea, or the cudbear lichen, on the banks of Loch Ewe
Visit to Stirling Castle on DHA tour to see the last of the Unicorn tapestry series being woven
Explanation of ‘corcur’ from Dwelly’s Gaelic Dictionary

About the pictures

Above is a small selection of textile-related images from Scotland, most of which I tweeted during our trip. My obsession with dye lichens was rewarded by finding Ochrolechia tartarea alongside Loch Ewe, and Lobaria pulmonaria  at Oban; Parmelia saxatilis and P. omphalodes were growing at many locations.  Note: I was looking, not collecting. A Gaelic-English Dictionary in a hotel room confirmed that in Gaelic crotal refers to boiling water method lichens, but corcur to orchil lichens. If you want to know what orchil is, or read more about my research and views on dyeing with lichens, please visit this page.

Turkey Red

I spent a week with Deb Bamford (aka The Mulberry Dyer) learning how to dye Turkey Red at a Summer School in 2013. Read about it from this blog post forwards. In Scotland I found remnants of the Turkey Red industry buildings at Alexandria, on Levenside. There is a great website about the Turkey Red industry here. And read this wonderful book:

Colouring the Nation: The Turkey Red Printed Cotton Industry in Scotland c1840-1940 by Stana Nenadic and Sally Tuckett. Published by National Museums Scotland. From Amazon here.

Unicorn Series: Stirling Castle and West Dean Tapestries

For more on the Unicorn Series, go here for the Stirling Castle story, and here for West Dean’s version.

 Glengoyne Distillery, Dumgoyne Glengoyne Distillery


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Oddments

photo

Packs of indigo and Rubia cordifolia, (Indian madder) shown with Phytosanitary Certificate

My latest excitement is today’s arrival of a parcel from India, containing indigo and Indian madder (Rubia cordifolia) from the excellent KMA Exports. I am sharing the consignment with a friend because the freight is expensive and costs more than the dyestuff, but it took just one day to arrive from Tamil Nadu. Sometimes a parcel takes longer from Okehampton. It would have been here earlier but import regulations into the UK now require fumigation which takes a bit longer; the Phytosanitary Certificate confirms that my consignment is free of Khapra beetle (Trogoderna granarium) and other quarantine pests.

Having tried Rubia cordifolia with Deb Bamford at Summer School last year I can’t wait to have another go. It produced the most astonishing colour on wool.

A highspot of recent weeks was a short trip to Finistère in Brittany, in the glorious weather also enjoyed in the UK that week. I enjoyed seeing fine examples of Breton embroidery, something about which I knew nothing, in the Musée Bigouden, Pont l’Abbé. There is an informative page about traditional Breton costume here from which I’ve learned a lot. You can see a photo of the embroiderers of Pont l’Abbé at the top of the page. Until I studied the caption I thought it was a very old photo, but it is dated to 1976, when I was about the age of some women in the picture. Perhaps that does make it a very old photo, come to think of it.

Several walks along the coast west of Douarnenez offered stunning views over the sea and as always, I was on the lookout for lichen. I don’t collect it, but I like to find it; my views on actually using lichen for dyeing are here. A knowledgeable colleague has told me that one of my images probably shows an orchil lichen, one of the Roccellae, which cheers me up now I’m back and the weather has changed.

The historic cork floats and netting tools, which I found rather beautiful, were in the window of shop selling fish in Audièrne. Without a given explanation, I must assume the carved names once indicated owners of nets. When I lived on the west coast of Scotland I remember several vitriolic exchanges over ownership of creels, buoys and nets. This appears to be a simple way of marking equipment.

 

Embroidery, Pont l’Abbé
Embroidery, Pont l’Abbé
Embroidery, Pont l’Abbé
Corks and netting tools, Audièrne
Orchil lichen?

I’m teaching three courses at Ardington School of Crafts from Wednesday. Natural dyes on Wednesday 9th and Thursday 10th, and shibori with synthetic dyes on Friday 11th. If you’re coming, I look forward to seeing you there.


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It’s all gone a bit Rumsfeld..

“… there are known knowns; there are things we know that we know.
There are known unknowns; that is to say, there are things that we now know we don’t know. But there are also unknown unknowns – there are things we do not know we don’t know.” 

United States Secretary of Defence, Donald Rumsfeld, 2002 

Australian Journey: bush Night
Australian Journey: Judbarra

 

With the Christmas break just round the corner I know that if I don’t hit certain things right now it will be endlessly harder to pick them up in the New Year. So I have stopped making new work (see above) and am  organising the references for my co-authored DHA paper.

I am into Harvard References. I don’t have an academic background but occasionally I stray into Dark Territory and have to abide by the mighty rules, one of which is correct referencing. Writing up the DHA paper has meant revisiting texts read and absorbed maybe five years back. I have been favoured with a good memory and this means I sometimes remember very well that I know something, but don’t remember how or why. If I recognised the need to know at time of reading I will have taken a note of a source.  But as is the way with research, sometimes I don’t always know the relevance of a fact or a comment until a few years down the line. Then it can become vital – and that’s when it all goes a bit Rumsfeld.

So to his much lampooned statement (which I have always felt is more sane than many suppose) I’d add the following:

“… there are known knowns; there are things we know that we know. We just don’t know where we read them…”

And I recommend the University of Exeter’s helpful online resource here.


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French Connections

I’m back from a trip to the DHA (Dyes in History and Archaeology) Conference in La Rochelle. La Rochelle hosted the ISEND Conference in 2011 and so I was already familiar with the conference venue – a former fishmarket, now the exhibition and conference centre  L’espace Encan.

This is a text-heavy post, so here’s a picture of La Rochelle to keep you going.

LaRochelle

La Rochelle

A DHA conference annually attracts a wide variety of delegates from various disciplines. This year there were about 90 of us. Our number included chemists, conservators, artists, historians, researchers working with natural dyes, and students at various academic levels. At a DHA conference you can find yourself sitting next to someone from the British Museum, the Louvre or the Rijksmuseum, or an independent scholar who is simply passionate about parchment. It is a friendly assembly and all are welcome. Even if, as a non-chemist, you sometimes sit boggle-eyed through muscular technical papers full of graphs, analysis and molecular data, there is always something to be learned. I’m told that in early DHA days (this was the 32nd meeting!) there was a heavy bias towards these more scientific analytical papers but that nowadays the balance is more even, with a good mix of historic /scientific presentations. The selection committee who choose proposed papers must have an intensely hard job. Of the 24 or so papers accepted, several intrigued me but as none have yet been published this handful of comments remains general.

Purple Parchments

One paper involved the analysis of  purple-dyed parchments. Very little work has been done to analyse the source of the purple colour in such codices and as far as I understand, there is currently no scientific evidence that shellfish dyes were used on the parchments. Non-invasive methods are normally used in their analysis, essential if precious manuscripts are to be studied without damage, and these methods can make it more difficult to identify dyestuffs. (With a parchment it isn’t so easy to remove a physical sample as it can be from a textile, where a loose fibre may be available).

There was a mention of dyeing parchment with orchil, and my ears twitched. Last year I was asked to dye some parchment samples with orchil – and dye they certainly did. But it was apparent that the temperatures and immersion involved in dyeing with orchil stiffened and damaged the parchment quality. I felt that this method wasn’t viable. Cold-dyeing seemed to yield a more sympathetic result but I have no idea to what extent the parchment quality was affected as I was only sent miniscule pieces of parchment to dye.

In the post-presentation question session it emerged that the term ‘dyeing’ means different things to different people. Some delegates considered ‘dyeing’ could be the layered painting on of dye and not dyeing by immersion, as working dyers think of it. Now, I should say that I tried painting orchil on too, but soon lost the will to live. It would be immensely protracted to paint on sufficient orchil to build up a good colour. That’s not to say it would be impossible, I just didn’t have the time or the resources to continue.

It will be interesting to learn more about this research. Maybe at Glasgow and DHA 33 next year? The dates are October 30th – 31st 2014.

Shearings and Clippings

Magnified images had been studied by the presenters which showed lumpy-looking particles in the red lake used in several medieval paintings. These indicated that they were reclaimed dyes from red-dyed wool, made into lakes for painting. The reclaiming of red lake pigment dyestuffs from clippings of dyed wool revealed that it made good economic sense to extract the dyes and to reuse them as painting materials. The dyeing of red, from whichever dye source, was expensive and thus waste material might be reprocessed. Again, I encountered problems with a mutual understanding. Initially I was confused by the words ‘shearings and clippings’ which were used by the presenters. I associate these words primarily with sheep-shearing!  In the paper the words referred to waste dyed cloth after cutting woven material – or yarn.

The finding of these ‘reclaimed reds’ isn’t in itself new. A 1996 paper by Jo Kirby and Raymond White goes into great detail (find it here) and also lists a  number of paintings in which red lake pigment dyestuffs have been found. Have a look. You may be amazed.

Networking

A couple of years ago, at DHA in Lisbon, I presented a paper about the trade in dye lichens from Angola through Lisbon. I have yet to publish this, for several complicated reasons. But I had an interesting conversation with another delegate which led me to sending a very small quantity of dye lichen and a recipe to the University of Évora. I heard no more, and forgot all about it. At La Rochelle my Portuguese colleague and  her team presented a paper in which they had measured and tracked the breakdown of the depsides and depsidones (the dye precursors) in the orchil preparation process until purple chromophores formed. Chromophores are the part of the molecule responsible for colour. The chemistry was patiently explained to me in a coffee break and I now understand rather more about the process that before – although I wouldn’t like to take an exam just yet. DHA is great for this kind of contact and co-operation.

DHA=GFZ: A Gremlin Free Zone

If you read the previous post you will now that I was co-presenting a paper at DHA 32  and I wrote about the snaggly-toothed IT gremlins that lurk for unprepared presenters. I am pleased to report that my eminent co-author, Zvi Koren, had done an admirable job on gremlin-bashing (he’s ace at puns too) and everything loaded and presented totally as expected. So did everyone else’s, and we all benefited from calm, unobtrusive technical expertise delivered by Florent Glatard of ARRDH- CRITT Horticole. Our presentation was really well-received but I will not be writing about it until formal publication.

Thanks to DHA 32 organisers Anne de la Sayette and Dominique Cardon

Anne de la Sayette is the Directrice of ARRDHOR – CRITT Horticole, a ‘centre of research, innovation and technology transfer in horticulture’. Dominique Cardon is well known to most natural dyers as author of Natural Dyes: Sources, Tradition, Technology and Science. She is also Emerita Senior Researcher at CNRS, the French national centre of scientific research. CIHAM UMR 5648 CNRS  (an institution, not a mathematical  equation..)  is one of the most important research centres in France for history, literature and archaeology of the Middle Ages. A new book by Dominique is about to be published but I don’t have the details: as soon as I do I will add them to a post.

Carnac

If you have got this far you deserve a pictorial prize. Using photos from DHA is tricky as I feel I should ask people’s permission before posting their images on a blog, so here is something rather special from the trip home.

Orchil lichen on stone at Carnac
One of the Carnac alignments
Viewpoint over Kerlescan alignments

I had never been to Carnac in Brittany until last week and I had no idea of the scale and breadth of the entire site. But it seemed most serendipitous to discover, on some stones of the alignments, a quantity of orchil lichen. Naturally, I did not touch it. But here are some images to reward stalwart readers. The orchil lichen is in the left hand image only.


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Reasons to be Stressful

Presentations

I’m halfway between two presentations. The first was for the 6 Guilds of Weavers, Spinners and Dyers at Stratford where I spoke about orchil and how the trade in lichen dyestuff reached global proportions in the late nineteenth century. I thoroughly enjoyed my day at Stratford which included a talk by co-speaker Joan Baxter on the way the East Sutherland landscape influences her tapestries. Her recent collaborative work with dancers Between the Web and the Loom was interesting and she showed some video clips. But I can’t find any images on the internet to provide a link beyond this one (about the dance) and this one (about the tapestry she wove).

The second presentation is for the Dyes in History and Archaeology Conference (DHA) in La Rochelle, France. That’s later this week, is about something else entirely, and it’s going to be rather sensational.

Friday 4th October

11:45          Treasures from a Leeds Dye Chemist: A Century-Old “Tyrian Purple”?

                   Isabella Whitworth, Zvi C. Koren

If you want to know more about the sensational, come to La Rochelle. Otherwise, I’m sorry, you may have to wait a little. To download the whole DHA La Rochelle programme, visit this page and follow the links at the bottom.

For the moment, here is a taster in the form of some images. You will see two men, both chemists. There is a brother and a sister, and the son of a famous father.

Charles Samuel Bedford
Annie Perkin, née Bedford
Arthur G Perkin, second son of Sir William Henry Perkin

Lectures and technology

Those who are of ‘a certain age’ will remember that one of the worst things that could happen when giving a lecture was that you dropped all the slides just prior to going on stage then reloaded them upside down, in the wrong order and back to front.

Technology wasn’t satisfied with such piffling levels of stress. So it created Macs and PCs and system updates; memory sticks and SD cards and PowerPoint and embedding. It now arranges that hosts provide an ancient laptop unable to read anything post 1910;  it organises missing leads, the wrong leads, deflating batteries, clickers that die, videos that won’t load and projectors which will have nothing to do with your laptop.

I have watched entirely respectable speakers show a presentation devoid of images because they haven’t checked their Mac presentation on a PC – or haven’t embedded their photos.

As a result I am obsessive about options. At the 6 Guilds event I took my own Mac laptop, own projector, requisite leads plus a boggling array of memory sticks and SD cards correctly formatted and checked out on a neighbour’s PC. In fact, the options proved unnecessary as the 6 Guilds laptop was up-to-date, the memory stick loaded, and two super-calm techies were in control.

For DHA, all presentations have to be sent in advance of the Conference which is good sense – in theory. You will be informed that something has arrived, but you still don’t know if the presentation shows exactly the way you designed it. So, when you get there, you need to check – and have some options up your sleeve. I didn’t do the DHA PowerPoint: my co-author did, for which I am deeply grateful. It can all be his fault.