Further alkaline extraction method tests and some puzzling results

April 18th, 2016

Following on from my recent alkaline extraction method experiments, I decided to try the method used by Krista Vajanto in her dissertation and described in my post of March 8th. So before adding a further set of samples, I left the dye baths to become acidic. This proved more difficult than I had expected, as the pH decreased a little and then remained stubbornly at around pH9 and refused to become more acidic. After a couple of weeks, I decided to add another set of samples anyway, which I left to steep for about 4 weeks. The dye baths looked very strongly coloured and I was hoping for well-dyed samples. Indeed, on removal from the dye baths the samples appeared deep in colour but most of the colour washed off, leaving the samples considerably paler than the first set, which had been in the alkaline dye bath for only 2 weeks.

I really don’t know how to interpret these surprising results. If the dye baths had been pH7 or below, I would have assumed that the acidic conditions had made the samples paler. This would have been in line with results from acidic modifiers which often result in the samples becoming paler. But in this case the dye baths were still alkaline, although less so than for the first samples. However, the dye baths had become slimy and viscous and I wonder if this is a sign that fermentation was taking place and the fermentation caused the colours to become paler?

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This photo shows, from the top: birch bark, alder bark, white willow bark, tormentil root, with 4 samples for each. For each dye, the pair of samples on the left is from the first dye bath (2 weeks) and the pair on the right is from the second dye bath (4 weeks). In each pair, the top sample is alum-mordanted and the lower sample is unmordanted. The photo quite clearly shows how much paler the samples are from the second dye bath. Very puzzling!

Workshop at Plumpton College

March 27th, 2016

Earlier in March I taught a workshop for my dear friend Sue Craig and the students on her “Grow Your Own Colour” course at Plumpton College Brighton. Although I no longer lead workshops myself because of my physical limitations, I am always happy to work with Sue and her students because Sue provides all the materials and equipment and prepares everything in advance and she and her students do everything that is required as far as the hard physical work is concerned. I just sit and talk a lot and give the orders, which suits me very well!

This course was “Marvellous Madder”, which showcases the remarkable colour properties of this amazing dye plant. Last time I did this workshop I attempted too much and rather over-worked the students, so we decided to limit it to 26 wool samples this time.

We used the madder as follows:

Use about 80% madder and wash the madder pieces in cold water to remove some of the yellow and brown pigments. Then pour boiling water over the washed madder pieces and leave them to steep for about 45 seconds. Then strain this liquid into a dye pot and repeat this process twice more. This forms the first “pour-off” dye bath. (See second photo below) NOTE: I usually make this “pour-off” dye bath because it helps to use up some of the yellow and brown pigments that might not have been washed out and that can make the red colour from the main dye bath too dull or brown.

Then simmer the same madder dye pieces for about 30 minutes, strain off the dye solution and leave to cool slightly. Then add the fibres and leave them to steep for about 45 minutes to one hour. If necessary, the madder dye bath can be heated gently but keep it well below simmering point. NOTE: madder can safely be simmered to extract the dye colour but it is better to keep the temperature below simmering point after the fibres have been added, otherwise the colour may become too brown in tone. The same madder pieces can be simmered at least once more to make a further dye bath; indeed, the same madder pieces can often be re-used two or three times. So if we had had time to do this at the workshop, we could have doubled or even trebled the number of samples we achieved.

After dyeing, the samples were modified. (Instructions for making and using colour modifiers can be found in my books.)

As so often happens at workshops where time is limited, the colours achieved were not as deep and intense as I would have liked, although we did achieve a wide range of shades. Had we been able to allow the fibres to remain for longer in the dye bath, we would have had some much richer reds.

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This photo shows 24 wool samples.

Each group contains a sample of no mordant, alum mordant, tannin (oak gall) mordant and rhubarb leaf base, in that order. From left to right the groups are: no modifier, acidic (vinegar) modifier, alkaline (soda ash) modifier, copper modifier, iron modifier, iron modifier followed by alkaline modifier (2 modifiers applied in succession)

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These samples, also wool, were dyed in the dye liquid poured off when preparing the madder dye bath. From left to right: alum mordant, no mordant

 

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Sue (left) and I obviously enjoyed ourselves!

More experiments with the alkaline extraction method

March 8th, 2016

I am very interested in the dyeing techniques of the past and recently I read Krista Vajanto’s dissertation on Dyes & Dyeing Methods in Late Iron Age Finland, (http://urn.fi/URN:ISBN:978-951-51-1790-8) which contains some interesting details about dyes and possible methods for achieving reds (or reddish colours) in areas where madder and madder-related plants were not available. I corresponded with Krista before her dissertation was published and conducted some of my own tests, which I wrote about in my book  A Heritage of Colour. Since then, I have been able to obtain some more information from reading Krista’s dissertation and I have started to experiment further.

One method that would seem to have been used in the Iron Age in northern Europe is what Krista calls “the fermentation of tannins”. Apparently tannin-rich plant materials such as barks and the roots of tormentil (Potentilla erecta) will give red or rust colours if treated in wood ash water or a similar source of alkali. This is very similar to what I call the alkaline extraction method, which I use mainly with madder root and buckthorn bark. In my method, the barks or roots are soaked in wood ash water with no application of heat and the fibres are dyed in this alkaline solution, usually without application of heat or occasionally at a very low temperature. After some time, fermentation will begin and the dye solution will start to become neutral and then acidic.

From my experiments using this method with madder root and buckthorn bark, I have found that if the pH becomes too acidic the red colours become more orange or rust in tone so, in order to obtain true reds, it is important to keep adding alkali to maintain a pH of at least 9. The method Krista used for her experiments with the tannin fermentation method differs somewhat from mine; she fermented the plant materials before adding the fibres, rather than adding the fibres to the wood ash water at the same time as the plant materials. In her dissertation Krista describes how, in her tests, the plant materials were steeped for four weeks in the wood ash water, which started off at about pH10, and then as the time passed the pH values decreased from alkaline to neutral and then to acidic and pH6 as the plant materials fermented.  The fibres were then added to the dye liquid and steeped for two weeks at room temperature. So the main difference between the two methods is that Krista does not add the fibres to the dye solution until it has fermented and become acidic, whereas I add the fibres together with the dyestuff and maintain an alkaline pH while the fibres are steeping in the dye pot and I do not allow the solution to become acidic if I am aiming for reds.

For my latest experiments I decided to first try my method and then the one described by Krista. So I set up some dye baths in glass jars, using alder bark, birch bark, white willow bark and tormentil root. For comparison, I also conducted the same test with buckthorn bark, which I have already used in several tests using the alkaline extraction method. (See my 2013 post Buckthorn Bark)

I half-filled the jars with wood ash water and then added the dye material and wool samples.

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The dye liquid became deep red after a day or so and I checked the pH of the solutions every day and added more alkali (wood ash water or soda ash) as necessary to maintain a pH of between 10 and 11.

The samples were finally removed after two weeks. Although they appeared deep red/pink as they were removed from the dye pot, the red colour gradually disappeared as the samples were rinsed and washed, leaving much softer, paler shades. This was interesting, as the colour remains red when using this method with buckthorn bark and does not rinse out.

Below is a photo of the colours achieved. (I would not describe any of the colours as “red”.) There are 2 skeins for each dye; the first skein in each pair is alum mordanted and the second skein is unmordanted.

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From left to right: birch bark, tormentil root, white willow bark, alder bark.

I will now leave the dye solutions to become acidic and ferment before I add a further set of samples to each dye pot.  Once my next tests are completed, I will write a further post on this topic.

For interest, below is a photo of skeins dyed in an alkaline solution of buckthorn bark, following the same method as described in the tests above. The dye bath was kept at around pH10 to pH11 and these skeins are definitely red.

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South Downs Yarn & colours from fungi

February 3rd, 2016

Part of the ethos underpinning South Downs Yarn, Louise Spong’s wool company, is a belief in the importance of making use of locally-available fleece, which can be traced back to the flocks from which it came and sometimes even to the individual sheep. The wool for Louise’s yarn comes from Southdown sheep and is sustainably sourced, single-flock wool from smallholders and farmers from the South Downs locality.

The same ethos determines the sources of the plants used to dye South Downs Yarn, so wherever possible the plants used are grown or harvested locally. This can sometimes be challenging, especially where plant sources of pinks and purples are concerned. Whilst virtually all other  colours can be readily produced from locally grown or harvested dyes, pinks and purples are more elusive. Pinks (and also purple) come mainly from the insect dyes, cochineal (found predominantly in parts of Central and South America) and sticklac (from India and South-East Asia). Madder root (Rubia tinctorum) and buckthorn bark (Rhamnus spp.) can sometimes give pinks in the coral range but will rarely give a true rose pink.

The most commonly used source of purple is the heartwood of logwood, Haematoxylon campechianum, from South or Central America. Purple can also be achieved from some species of lichen but lichens are protected in the wild and should preferably not be harvested for dyeing. Lichen purple is also not reliably fast and for that reason I would be reluctant to use this dye for anything I might want to sell or give to anyone else. Alkanet root (Alkanna tinctoria) will give a purple shade under certain conditions but the colours it gives are very variable and not always reliable.

Some time ago I discovered by chance another source of purple, when I added some walnut extract to a madder extract dye bath (both extracts from Earthues). This combination produced a pleasing purple-pink but, following further experiments, I found that this only occurs if the dyes are used in extract form and not when the chopped plant dye pieces are used. (See my earlier posts on this. Not what I was expecting & Walnut hulls & madder root again but no purples or pinks) I must conduct some more tests to see whether this colour can be regularly produced from this combination of extract dyes, as it could prove very useful.

To try and find other sources of pink and purple, I looked again through my dye sample books and decided to try dyes from fungi, in particular from species of Cortinarius.

For this South Downs Yarn fungi dyeing session we used Cortinarius semisanguineus, with an alum mordant and followed by an alkaline modifier. This gave pretty pinks. However, a further alum-mordanted skein followed by a copper modifier after dyeing did not give the purple tones I had hoped for, but a rather dull beige pink. I’m not sure why this was the case but I suspect the exhaust dye bath which we used was too weak to give a pink deep enough to produce the desired result from the copper modifier.

I also had the remainder of a small amount of the fungus Hapalopilus rutilans, kindly sent me from Finland by Leena Riihela for some tests for my most recent book  A Heritage of Colour, and which gives a pretty lavender purple dye colour. I had read that extracting the colour from Hapalopilus rutilans at pH9 to 10 would improve the colour, so I added a small amount of soda ash to bring the water to pH9 when I simmered the fungus to extract the colour. Unfortunately this proved not to have been such a good idea, as the extracted dye colour seemed paler rather than more intense and pink rather than purple in tone and it dyed the skein a rather pale dull pink. (I had probably also added too much fibre for the amount of dyestuff I had and this made the colour paler than I had wanted. Note to self: Don’t add too much fibre in future when you know there isn’t really sufficient dyestuff for a reasonably strong colour to be achieved, especially when you haven’t got enough dyestuff left to re-dye the fibres!) I re-simmered the used dyestuff together with the last remaining few pieces of fungus and used it to dye two small skeins, which this time became a prettier colour, but still pink in tone. I suspect this was because some soda ash solution had been absorbed by the pieces of fungi and had an effect on the dye bath when the fungus was re-processed. However, as this fungus is not readily available I doubt whether I would be able to obtain enough to make it a useful source of purple.

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Cortinarius semisanguineus (photo courtesy of Leena Riihela)

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Shades of pink from Cortinarius semisanguineus (Alum mordant + alkaline modifier) The paler shades are from exhaust dye baths 1 & 2 (Photo courtesy of Louise Spong of South Downs Yarn)

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This skein was dyed in the third exhaust of the Cortinarius dye bath. (Alum mordant + alkaline modifier)

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Hapalopilus rutilans (photo courtesy of Leena Riihela)

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Small skeins dyed in Hapalopilus rutilans after re-simmering the used dyestuff as described above.

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Colours from Hapalopilus rutilans without pH adjustment for colour extraction. The top sample is alum-mordanted & the lower sample is unmordanted.

 

These results indicate that Cortinarius spp. of fungi can be useful sources of pinks. I am also experimenting with the alkaline extraction method on birch bark to see whether this might yield a pink colour. More information about this will follow later.

Autumn Colours

November 2nd, 2015

Autumn seems to have come quickly this year and the garden reflects this change in the seasons. I love the colours of this helenium.

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The forest pansy ( Cercis canadensis) always looks spectacular at this time of year, especially with the light shining through the leaves.

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Even its fallen leaves have a beauty of their own

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Autumn wouldn’t be the same without pumpkins

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The autumn colours inspired me to dye some skeins of South Downs Yarn wool, using dyes harvested from the garden.

From left to right: dyer’s broom, buckthorn leaves plus madder root plus woad, dahlia flowers plus madder root, dahlia flowers (All alum mordant)

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Shearing Day for the Nepcote Flock

June 29th, 2015

Saturday June 20th was the day set for shearing the Southdown sheep from the Nepcote Flock. Luckily the weather was dry, although rather cloudy, and Louise Spong and I joined the flock’s owners, Graham Langford, Hari Doman and Martin Rolph, at the field. Louise and I wanted to look at each fleece as it came off the sheep’s back so we could select those we wished to reserve. As it turned out, the fleeces were generally of such good quality that we selected nearly all of them.

The photos below are a reminder of a great day with excellent refreshments too!

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Here are the sheep waiting their turn for shearing

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Number 11’s fleece looked good to me, so I made a note of the number and waited for her to be shorn.

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Number 11’s turn has come

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The fleece starts to come off

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Number 11 without her fleece

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Here is her fleece rolled up

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This lamb was very interested in the fleeces

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These two watched the proceedings with interest

 

 

My garden in June

June 11th, 2015

In the five years since we moved here I have managed to transform our small garden into one which resembles my old garden but on a much smaller scale. It is full of plants to attract bees and butterflies and other beneficial insects and of course I have a small dye garden too.

Here are some images of my garden in June:

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Woad in flower

 

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Herb beds with a self-seeded foxglove in front of the angelica

 

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Angelica gigas flower heads

 

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William Morris rose

I will add some photos of my dye garden in the next post.

Dyeing greens for South Downs Yarn

May 12th, 2015

I have been doing more natural dyeing with Louise Spong of South Downs Yarn, (see link on the right of the home page), this time focusing on greens. The photo below shows a range of green shades from one of our dyeing sessions.

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Although green is the most common colour in nature,  producing green from natural dyes is not as straightforward as one might expect. Mossy greens can usually be achieved by using an iron modifier on yellow-dyed yarn and using a copper modifier on fibres dyed with plants such as weld often gives lime green. However, a true grass green is almost impossible to obtain from a single dye and has to  be achieved by dyeing blue over yellow or vice-versa.

The photo below of colours from weld shows from left to right: weld + iron modifier, weld with no modifier, weld + copper modifier.

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There are numerous sources of yellow but indigo is the only reliable source of true blue. I tend to prefer to dye yellow first and then use the blue dye; I feel this gives greater control over the final colour because the indigo blue can be added gradually by dipping the fibres in the vat several times. If the vat is weak and each dip is brief, the green colour can be built up gradually until you reach the desired shade and depth. Some dyers prefer to start with blue fibres and then over-dye them with the yellow dye and this also gives good results. The shade of yellow determines the shade of green. Dyeing blue over a bright clear yellow gives grass green; mustard yellows tend to produce mossy greens, whilst over-dyeing pale yellow or a beige yellow often gives a turquoise green. It is also important to remember that most yellow dyes require a mordant, in which case the yarn you use will need to be mordanted even though indigo does not need a mordant. Yellow dyes that do not require a mordant include rhubarb root and saffron. However, saffron may be considered too expensive to use in the dye pot, although about 5% should be enough to achieve a reasonable yellow..

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The photo above shows the development of turquoise green from pale yellow over-dyed in indigo.   Later in the year I shall be writing an article on dyeing greens for the “Journal for Weavers, Spinners & Dyers” and this will give more information and include several photographs.

More about the Nepcote Flock of Southdown sheep

April 20th, 2015

 

It’s lambing time here and lambs from the Nepcote flock of Southdown sheep can be seen in the fields in Findon village, where I live. I took my granddaughters to help bottle-feed one of the lambs, who was rather weak, and they were thrilled to sit with the little lamb on their laps.

 

091 sheep & lambs

 

I have also been spinning a Southdown shearling fleece from the Nepcote flock. It has a reasonable staple length (about 4 to 5 cms), is soft and fine in texture and is producing a pleasing springy yarn. This fleece was one of three shorn recently from shearlings being prepared for showing later in the year, by which time they should have grown another lovely fleece just ready for the show.

 

The photo below shows washed fleece ready to spin and a handspun skein

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The photo below (taken early in the evening) shows Graham Langford, the co-owner of the sheep, followed by some of his shearlings, including those from which the fleeces came. When the rest of the flock is shorn in June I shall be looking out for more shearling fleeces.

 

Graham herds his sheep

 

 

 

Colours of the Romans

February 23rd, 2015

 

Last year I dislocated my hip for the third time and sadly had to cancel the workshop “Colours of the Romans” at Fishbourne Roman Palace. This was particularly frustrating, as I had had to postpone a previous workshop at Fishbourne a couple of years ago when I dislocated my hip the first time. Fortunately, this earlier workshop was re-scheduled but my physical health has become so  unreliable that I have decided to “retire” from workshops, except for those on a one-to-one basis at my home.

 

As I had already done all the preparations for “Colours of the Romans”, including printing off all the information sheets and sample cards and preparing the wool sample sets, I decided to offer the workshop to the education department at Fishbourne, rather than let all my work go to waste. Katrina Burton, Head of Learning at Fishbourne, and Beverly Lee, the Education Officer, took up my offer and earlier this year they came to my home for the workshop. Louise Spong, from South Downs Yarn, also joined us and assisted with the heavier physical work, which has become too much for me following my recent hip surgery.

 

The dyes used by the Romans included madder, kermes, weld, woad, walnut hulls, oak galls, saffron and lichen purple. With the exception of kermes, which is no longer available, these were the dyes we used on the course.

 

According to Pliny the Elder, orange, red and purple were colours worn by priests and priestesses. Purple was the colour for high officials and the purple clothing of Emperors was dyed purple using a dye from shellfish of the Murex species. The dye colour was known as Tyrian or Imperial Purple and vast quantities of shellfish were required to produce relatively small amounts of dye material. This mollusc dye was overused and the supply of shellfish gradually dwindled. By the Middle Ages, the Tyrian Purple dye industry had become considerably reduced and with the fall of Constantinople in 1453 it more or less disappeared. A purple dye from the lichen Roccella tinctoria was used by the Romans to simulate the purple from shellfish.

 

MADDER (Rubia tinctorum)

Madder is a source of red dye and, according to Pliny, it was cultivated near Rome c.50AD. It is interesting to note that, although there is evidence that the Romans used madder when they were in Britain, its use in Britain appears to have ceased for a period after the Romans left (c.410AD). This would seem to suggest that the Romans imported madder from Rome as a prepared dried dyestuff, rather than cultivating it in Britain.

KERMES (Kermes vermilio)

This red insect dye comes from the shield louse Kermes vermilio, which lives on the kermes oak found in various parts of the Mediterranean. Today kermes is very difficult to obtain, although the insects may still occasionally be found on host trees around the Mediterranean.

WELD (Reseda luteola)

Weld is one of the most ancient dyes and has better colour-fastness than most other yellow dyes. The yellow from weld was the colour worn by the six Vestal Virgins and was also the colour of Roman wedding garments.

WOAD (Isatis tinctoria)

Woad was used by the Romans as a source of indigo blue dye. Indigo from Indigofera tinctoria was also used by the Romans, but as a paint pigment rather than as a textile dye. It was probably brought to Rome from India in small quantities via the land route.

LICHEN PURPLE (Roccella tinctoria / Ochrolechia tartarea)

This dye is sometimes referred to as orchil. Relatively few species of lichens will give purples and as lichens are protected they should never be harvested indiscriminately from the wild. For the workshop, we used the lichen Ochrolechia tartarea, as Roccella tinctoria is not found in northern Europe. For experimental purposes, make sure you have identified the lichen accurately and use only a very small quantity, for example a piece about the size of a 50p coin. To make lichen purple solution, put the lichen into a strong glass jar and add 2 parts water and 1 part household ammonia. Put the lid on firmly and leave the solution for several weeks, shaking or stirring it two or three times each day. The solution will become a deep purple colour and is then ready to use. (Note: stale urine contains ammonia and can be used instead of household ammonia) When the solution is ready to use, strain it carefully into a dye pot, add more water and add the fibres to be dyed. Simmer them gently for 45 minutes, turn off the heat and then leave them to steep overnight. Then rinse well. Lichen purple is not a very fast dye and materials dyed with lichen purple should be stored in a dark place away from daylight. (NB Ammonia gives off unpleasant fumes and should be used with caution.)

OAK GALLS (Quercus spp.)                                                             

Oak galls are rich in tannin and were used by the Romans in combination with iron to make a black dye. When used alone as a dye, oak galls give tan and light brown colours.

WALNUT HULLS (Juglans spp.)

According to Pliny, the outer green hulls of walnuts were used as a brown dye for wool and hair.

SAFFRON (Crocus sativus)

According to Pliny, saffron was cultivated in Abruzzo and Sicily & was used as a yellow dye. Although saffron is very expensive, only a very small amount is required for dyeing and for the workshop samples we used only about half a gramme.

 

Another dye reportedly used for yellow was turmeric, from the roots of Curcuma longa, which was imported from the Orient during Imperial times.

 

Alum

The Romans used alum as a mordant and also iron but, as with madder, it is likely that alum was imported from Italy for Roman use and was not available in Britain after the departure of the Romans until it was imported in the later Anglo-Saxon period.

 

The photo below shows the colours we achieved on the samples we dyed at the workshop.

 

011 workshop samples for blog

 

 

Top row left to right: weld, weld overdyed with madder (orange shade), madder, madder overdyed with woad, lichen purple & walnut hulls

Middle row left to right: saffron, saffron overdyed with woad (greens), more saffron, walnut hulls overdyed with woad, walnut hulls overdyed with weak lichen purple, walnut hulls overdyed with madder, walnut hulls, weld overdyed with woad (green)

Lower row left to right: oak galls, oak galls plus iron (grey), oak galls overdyed with woad, woad, lichen purple overdyed with woad, lichen purple & lichen purple plus clear vinegar (reds)

 

More information on most of these dyes can be found in my latest book “A Heritage of Colour”.