Persicaria tinctoria | Isabella Whitworth

October 20, 2015
by isabellawhitworth.com 4 Comments

Blue and Black

Indigo pigment

I’m trying to use my Japanese indigo (Persicaria tinctoria) before frost hits and kills it, and it won’t be long. I planted it late this year and have only managed 5 ‘picks’ which were made around 15 days apart, to allow for regrowth. I had enough prepared work to dye in the first vats, but for the last two ‘picks’ there was nothing ready. Not wanting to waste the precious crop I have endeavoured to make pigment, which basically involves reducing (by evaporating) the indigo, in its alkaline, oxygenated state, down to a thick paste, and then powder. This can be reconstituted into a dye vat at a later date.

Japanese indigo growing in Devon

Leaves in water heated in a bain-marie arrangement

First filtration through gauze

Filtered liquid still contains indigo

Indigo paste

Drying paste

Dried out paste

A friend helped me with basic instructions but mostly I had to experiment. I probably wasted some indigo because I didn’t find a way of filtering efficiently. There also seems to be more leaf material in it than I hoped as it looked greeny-blue at paste stage. In a hot, dry climate like India shallow containers of liquid evaporate fast but here it took days, even on the top of the central heating boiler. It was a race to evaporate the goo before it went mouldy. I forgot to weigh the leaves but I think there was about 1 kg, which reduced to 5.3 grams of indigo pigment. There is a full explanation of the way I process Japanese indigo before the evaporation stage here so I won’t repeat the method.

Bideford Black

With pigment-making on my mind, I went to see the new exhibition at the Burton Art Gallery and Museum at Bideford. It’s called Bideford Black: The Next Generation and it centres on a rare and beautiful black earth pigment which emerges from the North Devon cliffs. In the past ‘Biddiblack’ (as it was known), has been used in paint manufacture, for making mascara, camouflaging military vehicles, in boatbuilding etc., and commercial mining for it continued until 1969. Artists working in a traditional manner, or with traditional materials, have valued its velvety dark strength and subtle tones. I had a chance to try it in the Burton Gallery last week, as can all visitors to the show. Bideford Black: The Next Generation is an unusual and unconventional exhibition and it’s certainly not traditional: participating artists responded to the pigment in diverse and often thought-provoking ways. Links below.

Grinding Bideford Black

Sizing stretched calico with soya milk

Stretched and sized Ahimsa (Peace) silk painted with different concentrations of pigment, made as a sample

Bideford Black and local earth pigment combined

Masked plate in background ready to roll up with Bideford Black pigment

‘Ghost print’ from my original drawing from the RJ Lloyd Collection of Devon ceramics

Inked plate after first impression. Drawing made from RJ Lloyd Collection of ceramics

I wanted to find out if the pigment could be painted onto sized cloth and the exhibition organisers offered me some Bideford Black to take home and try out. Using a rare pigment 300 million years old was moderately inhibiting and my efforts also felt stuffy and old-hat after seeing the exhibition. Nevertheless, stuffy and old-hat is what I do, so I got on with it.

Using the soya milk recipe generously published online by John Marshall (see link below) I stretched and sized silk and cotton and worked experimental pieces. I wasn’t trying to make anything, just seeing what the pigment would do. The black was initially ground in a pestle and mortar and then mixed with more soya milk as a binder. I found that a small amount of gum arabic assisted in holding it together, stopping moisture bleeding outwards from painted shapes. The fabrics now need to cure.

Finally in this tale of blue and black, I was lucky to book a place on a monoprint workshop run at The Burton by Grizel Luttman-Johnson. We inked up perspex plates with Bideford Black printing pigment, which Grizel had prepared by grinding and mixing the Black with a binder and linseed oil. We then placed paper on the inked plate and made drawings on the reverse of the paper. Pressure caused ink to be picked up and an impression made on the front of the paper. The plate could be used again to pick up a ‘ghost print’, which created a kind of negative image. It was a very enjoyable day, well-led by Grizel.

Some links to the Blog for Bideford Black: The Next Generation

The Geology of Bideford Black

The Nature of Black

Next Generation: Artists Selected

Launch and work information

Grizel Luttman-Johnson

I am indebted to Michel Garcia and John Marshall for their freely published information:

Information on Michel Garcia’s DVD on natural dyes here

John Marshall instructions for making soy milk here

August 24, 2014
by isabellawhitworth.com 2 Comments

Harvesting Japanese indigo

Blue stains which developed after rubbing Japanese indigo leaves onto paper

I planted out my Japanese indigo (Persicaria tinctoria) several weeks ago, having grown it all from seed. This week I picked some leaves and rubbed them on the page of my sketchbook to see if any blue appeared. It did (ignore the buff coloured stain to the left of the image, which is nothing to do with it). From this I knew that I could make a vat from the crop.

I began by picking half a bucketful and testing it as a small vat. I achieved a very good blue, which was used to overdue some cochineal-dyed scarves I had shibori-tied ready and waiting. You can see the result in the gallery below.

On the second vat I used a whole bucketful of leaves, rammed down hard. I just pick the tips, like tea: not the whole stalk. I sometimes weigh the leaves before processing but the material was wet after rain and there didn’t seem much point. I don’t always strip the leaves from stalks either, so a known dry weight is somewhat academic because the stalks don’t, as far as I know, produce any colouring matter.

On the day I dyed the second bucket I live-tweeted the various stages with images and received a good response. I think more and more people are trying to grow, and dye with, their own indigo.

With colleague Christina Chisholm I co-authored a piece on growing and using Japanese indigo for the Journal for Weavers, Spinners and Dyers in 2011. It was a free download and you can still access it here so I don’t have to write it all out again. We included some information on growing the plant in two distinct climates (Devon and north east Scotland). Christina has much more experience with dyeing wool, so fibre dyers might find her comments useful. If I were to be able to edit the article I’d make a couple of additions / amendments:

1. I have since found that I don’t always see a blue froth when I whisk up the strained dye bath. Instead, the sherry-coloured liquid darkens and looks greener – but the froth is often colourless. Why? No idea. These days I have stopped using soda crystals and use washing soda instead. Maybe that’s the reason.

2. I have found that leaves are often ready whether or not they have the red/blue tinge shown in the Journal download document. What I have heard since (but don’t know if it’s true) is that you need to use the leaves before the plant produces flowers.

3. I try to encourage flowers for seeds each year and there is some urgency about this as in the UK the plants die with the first big frost. I mark a few vigorous stalks early on by tying a conspicuous ribbon round each one. Then I can’t pick them by mistake. I let these stalks develop flowers as early as possible.

Leaf tips after gathering

Bain-marie used to heat leaves in water

Leaves are crushed in the liquid

Leaves are sieved and squeezed out

Passing liquid from bucket to bucket to oxygenate

Liquid after addition of washing soda and oxygenation

Leaves for composting

Cochineal-dyed scarves and indigo dye-god

February 7, 2014
by isabellawhitworth.com 4 Comments

Made Not Manufactured: Steve Kenward

Back in 2011 photographer Steve Kenward started on a mission. It was to be an unfunded personal project, of more or less infinite scope, which he called Made Not Manufactured. His idea was to travel the British Isles to photograph ‘people that use traditional crafts to make something that still has relevance today.’ Steve’s paid work as a freelance photographer would fund the entire project which includes his travel, accommodation, and any other personal expenses.

He put the word out for craftspeople / participants through the Heritage Crafts Association (HCA) and soon found that makers of objects such as baskets, boats, rakes, bowls, knives and clocks began to contact him. You can see the results of this committed photographic portrait of British craftsmanship on Steve’s website here. I contacted him as a dyer, and feeling that natural rather than synthetic dyes were more relevant to his ‘traditional’ aims, I made an indigo vat from my crop of Persicaria tinctoria for his day in my dyeroom. Up in my studio I worked with a beeswax resist on the beginning stages of a silk scarf. With Steve’s permission I am including some of his images below.

Steve has photographed 43 craftspeople (plus 13 dogs, including mine) and travelled 5,300 miles – at the last count. Until yesterday, I believed his arrangement to exhibit the complete body of work at the Weald and Dowland Museum in Sussex in August was still going ahead. It seemed the ideal venue to celebrate the work of so many makers, some of whom were prepared to demonstrate their craft, and show Steve’s unique collection of photographs. But something has gone seriously amiss; it seems there is no funding to support the exhibition project and the arrangement has been cancelled.

I feel disappointed for Steve who has worked extremely hard to achieve his aims. He is an unobtrusive but enquiring observer as his photographs demonstrate but also a delightful guest: even the dog approved, although she took exception to having a tripod in the house.

Steve is now looking for another exhibition venue for this body of work. If you know of somewhere suitable, please contact Steve through his website and while you’re there view other images of his impressive project.

Footnote: I resolved that my dog would never appear on this blog, but here she is, as seen by Steve Kenward. As today is her 100th birthday in doggy years, I think there is something to celebrate.

Isabella Whitworth

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

Tag Archives: Persicaria tinctoria

Blue and Black

Harvesting Japanese indigo

Made Not Manufactured: Steve Kenward