Archive for the ‘General Dye Information’ Category

Dyeing with safflower petals

Tuesday, August 9th, 2016

Recently I was asked to dye some samples using safflower petals from Nepal. The dyed samples are to be exhibited at Edinburgh Royal Botanic Garden as part of an exhibition highlighting the flora of Nepal.

Safflower is a thistle-like plant and nowadays it is grown mainly for the oil from its seeds, which is used in salad oils and margarine. It is also occasionally referred to as “bastard saffron” because it is sometimes used as a substitute for the true saffron from the stigmas of an autumn-flowering crocus. Stems of safflower are often sold for dried flower arrangements.

Safflower has been used by dyers for centuries. It was one of the dyes identified on early Egyptian textiles and in the East it was also used to make pigments and cosmetics. Safflower is remarkable because both a yellow and a red dye can be extracted from its petals.

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The photo above shows a range of yellows and reds from safflower petals.

The red dye was used from early times in India and Japan to dye cotton and silk shades of vibrant pinks and orange-red, which tend to fade with the passage of time and frequent exposure to light. The yellow dye, although deep and brilliant at first, also has relatively poor fastness. The red dye from safflower was used to dye the tapes tied around legal documents – hence the term “Red Tape”.

To dye with safflower, use at least equal weights of dyestuff and fibres. (Stronger colours will result if you use twice the weight of the fibres to be dyed.) No mordant is required for pinks and reds. Although no mordant is necessary for yellows, using an alum mordant will improve fastness.

Note: the same petals can be used for both yellow and red.

The yellow dye can be applied to animal and vegetable fibres. The red dye, which is applied at room temperature, is suitable for cotton, linen and silk, but not for wool, which does not take up the red colour.

Dyeing reds with safflower is not straightforward, so below are some details.

First of all the yellow dye must be extracted from the petals. It is advisable to wear rubber gloves or your hands will become stained. Tie the petals up in a piece of muslin or old net curtaining and immerse this bag of petals in a bucket or bowl of cool water and leave to soak for a while. Then start to press and squeeze the bag to extract the yellow dye. Remove the bag from time to time to check how much colour is still running out. When the water in the bucket is strongly coloured and the petals no longer yield much yellow dye, squeeze out the excess water from the bag. Remove the petals and put them into a pan or plastic container and reserve the yellow dye for a dye bath later.

To extract and then apply the red dye,  first cover the petals in your container with enough cold water for your subsequent dye bath. Then add enough washing soda to bring the solution to pH 11 and turn the petals reddish-brown. Leave for about 1 hour, then squeeze the petals well and strain off the liquid. Don’t throw away the petals because the same petals can be used again for paler pinks, following the same processes.

Then add enough clear vinegar or lemon juice to the strained-off liquid to bring the solution to pH 6. It should now be bright red and ready for use.

Do not heat the dye liquid, but add the fibres and leave them to soak for several hours or overnight. Rinse well and dry away from direct sunlight.

Silk treated in the red dye bath becomes coral or orange, rather than pink. This is because the acidic dye liquid that contains the red dye also contains a second yellow dye, which is taken up by silk but not by cotton.

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The photo above shows from the top: coral/orange on silk and red on cotton

To produce pink shades on silk an extra procedure must be followed. First add some cotton fibres to the red dye liquid as above and leave them for several hours or overnight to absorb the red dye.

Then discharge this red dye from the cotton fibres back into a solution by placing the dyed cotton into an alkaline solution of water and washing soda at pH11. Soak the cotton in this solution for about 30 minutes or until the solution becomes red.

Then remove the cotton, acidify the solution to pH6 as described above and add the silk fibres. Leave them to soak until they have become pink.

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The photo above shows pinks on silk after the extra step.

Dyeing yellow with safflower petals is much simpler. Put the dye liquid into a dye pot, add the fibres to be dyed and heat to simmering point. Simmer for 30 to 45 minutes then turn off the heat & allow the fibres to cool down in the dye bath. Then remove them and wash and rinse them.

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This photo shows a range of yellows from safflower on wool (top), silk (centre) and cotton (bottom)

 

 

Dyeing large quantities of woollen skeins

Sunday, May 15th, 2016

A friend asked for help as she wanted to dye one kilo of handspun woollen skeins all the same colour. Dyeing such a large quantity of fibre is not easy, unless one has suitable equipment. I don’t have a pot large enough which could be heated and I no longer have a large Burco boiler, so the only option seemed to be to use a plastic container and opt for cool dyeing. Cool mordanting with alum is not a problem, as long as the fibres remain in the cool mordant bath for at least 24 hours and preferably longer. However, cool dyeing limits to some extent the dyes which can be used, as not all dyes can be successfully applied without heat.

The colour my friend chose was the pale green/yellow shown in the top sample below:

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To achieve this colour, I decided to apply an alum mordant and then dye with weld extract, followed by indigo. I already have a large plastic container I keep for alum mordanting and fortunately it was just large enough for the quantity of wool, so I filled the container with cool water, added the alum mordant and left the yarn in the mordant bath for a couple of days.

I decided to use a large plastic garden trug as my dye pot, so I dissolved the weld extract in boiling water and added it to the cool water in the plastic trug.  I stirred well and then added the wetted-out yarn and allowed it to steep in the dye bath for about 24 hours, by which time it had become a suitable shade of yellow and was evenly dyed.

The final step was to make an indigo vat, also in the large plastic garden trug. The wool was then over-dyed in the indigo vat.

Although the trug seemed large enough for the quantity of wool being dyed with weld, I think the wool probably needed even more space in the indigo vat, as the results were somewhat variegated. However, the colour on the sample was also variegated and my friend was pleased with the results of our labours, so all was well.

The photo below shows the dyed skeins:

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I then decided to dye a further kilo of wool, this time Romney Marsh fleece from local sheep, processed into yarn at Diamond Fibres in East Sussex. I wanted a colour suitable for a jacket that I could wear with most things and as I would have to dye without heat I chose to use buckthorn bark, which responds well to cool dyeing and which would, I hoped, give a caramel colour.

I simmered up about 200gms of buckthorn bark and then strained the dye liquid into the water in the trug. I added about 1 teaspoon of walnut hull extract in the hope that this might make the shade slightly browner in tone. (However, my initial feeling that walnut might not dye well without heat probably proved correct, as there is little evidence of any walnut influence in the final colour.) I added the wool skeins, which absorbed the dye more quickly than I had expected and I removed them after about one hour, rinsed and washed them and then left them to dry. These skeins also appear variegated but not this time because the trug was too small for the yarn. Buckthorn bark tends to change colour a little when left to dry in the light and it is important to open up the skeins and move them around, so they dry evenly. However, because the skeins were so dense and thick it was more difficult to open them up, so the final colour effect is variegated. Fortunately, I like this effect anyway and, although I had been aiming for a more caramel tone, I am also pleased with the colour.

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The final results.

Further alkaline extraction method tests and some puzzling results

Monday, 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!

More experiments with the alkaline extraction method

Tuesday, 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

Wednesday, 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.

Dyeing greens for South Downs Yarn

Tuesday, 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.

Colours of the Romans

Monday, 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.

 

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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”.

 

Wonderful Woad!

Sunday, October 12th, 2014

 

Following a remark by friend and fellow-dyer Sue Craig that, if woad flowers gave a yellow colour, this could then be over-dyed with woad blue to give green, I felt moved to try this for myself. It seemed particularly useful for those years when one has a bumper crop of woad and would be unlikely to need the vast number of seeds the flowers would produce.

 

My experiments showed that, sure enough, yellow woad flowers do indeed give yellow dyes, which can be over-dyed in a woad vat to give pretty greens. Following this method, unmordanted wool produces a sage green and wool mordanted in alum gives a grass green.

 

To dye yellow with woad flowers, just use the usual simmering method and use at least 100% woad flowers for really rich colours. If you use both unmordanted and alum-mordanted wool, two different shades of green can be achieved, as described above.

 

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The photo above shows, from left to right: 1. woad flower yellow (no mordant), 2. number 1 over-dyed in the woad vat, 3. woad flower yellow (alum mordant), 4. number 3 over-dyed in the woad vat                                     (NOTE: No 2 is less blue & more green in tone in reality.)

 

Once woad leaves have been used to make a woad vat, the same leaves can be used again to make a dye bath for pinks and tans. So when you make a woad vat for blues, don’t throw away the leaves but retain them to use again. Just simmer these used leaves for about 30 to 45 minutes to extract the pink-tan dye, strain off the dye liquid and add the fibres (unmordanted and/or alum-mordanted). Simmer for 30 to 45 minutes, leave to cool, then rinse and wash as usual.

 

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The photo above shows, clockwise from top left: pale blue from the woad vat, darker blue from the same woad vat, pink from the leaves re-used after they have been processed for the woad vat (alum mordant), pink from the leaves re-used after they have been processed for the woad vat (no mordant)

 

This means that it is possible to achieve blues from the woad vat, pinks and tan from the same woad leaves after they have been processed for blues for the woad vat, and greens from the yellows produced from the flowers and over-dyed in the woad vat. Oh, and I’m forgetting to mention the pinks and soft greens available from the woad seeds! (See my latest book “A Heritage of Colour” for details and a photo of the colours from woad seeds.) Woad is indeed a remarkable dye plant!

 

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Mediaeval Dyes

Monday, June 10th, 2013

 

Following on from my earlier posts about Anglo-Saxon dyes, I thought I’d write a little about the dyes used in mediaeval Europe, from around the 9th century to the beginning of the 16th century.

 

As archaeological evidence and the technical analysis of textile fragments indicate, during this period dyers had access to a wider range of dyes as trade developed and increased. Indigo from woad (Isatis tinctoria) remained the main source of blue and madder ((Rubia tinctorum) was the most common source of reds, with kermes (Kermes vermilio) and sappanwood (Caesalpinia sappan) also being used. Weld (Reseda luteola) and dyer’s broom (Genista tinctoria) continued to be used for yellows and other sources of yellow included heather (Calluna vulgaris), bog myrtle (Myrica gale), Persian berries (Rhamnus spp.), Venetian sumac (Cotinus coggygria) and sometimes also saffron (Crocus sativus).

The Imperial or Tyrian Purple dye from shellfish, famed in the ancient world, was still being used, albeit on a much smaller scale, and some species of lichens were also used in many parts of Europe to produce a vivid, if less permanent, purple colour. The tannin/iron complex remained the most common method of creating black, although the preferred, but more costly, method was to use red, blue and yellow dyes in sequence.

There were also apparently regional differences in the use of colour. By the 11th century Flanders was known for green, the Rhineland for black and Britain for red. Within England itself, some towns were licensed during the mediaeval period to produce certain colours – for example, York for red and purple, Lincoln for green, scarlet and grey, Coventry for blue and Beverley for blue and red.

 

3 dyed skeins p6 - Copy

 

From left: Reds and rust from madder (alum mordant), brown & tan from walnut hulls (no mordant), gold & yellow from weld (alum mordant), moss greens from weld + iron modifier and blues from woad (no mordant)

 

40 black overdye p.44 lower - Copy for blog

 

Black from madder + weld + woad (alum mordant)

 

221 lichen purple samples p137 centre - Copy for blog

 

Purples from the lichen Ochrolechia tartarea (no mordant)

 

Trade flourished in the Middle Ages and the most expensive of all dyestuffs was the insect dye, kermes (Kermes vermilio), from a shield-louse that lives on the kermes oak, Quercus coccifera, found in various parts of the Mediterranean. Sappanwood, from the heartwood of the tree Caesalpinia sappan, was imported into Europe in the later Middle Ages from India, Ceylon and Java and gave red colours. The wood and the dye were known locally as “bresil” or “brasil” and when at the end of the 15th century Portugese explorers found a related tree, Caesalpinia echinata, growing in the country now known as Brazil, they named the country “terra de brasil” after the tree and the red dye from Caesalpinia echinata was called brazilwood. Sappanwood was brought into Europe in surprisingly large quantities and 80% of the reds analysed on fabrics from around 1100 to 1450 prove to have been dyed with at least some sappanwood. It was added to madder dyebaths to enhance the colour and was also used for browns and for some compound colours. Sanderswood (Pterocarpus santalinus) from India and Ceylon was also introduced in the later Middle Ages and was used for reddish rusts and compound colours.

 

247 kermes p149 upper left - Copy for blog2

 

Kermes (Kermes vermilio)

 

248 kermes samples 1 p149 upper right - Copy for blog

 

Red from kermes (alum mordant)

 

Mediterranean alum became more widely available and was imported into Britain from Italy, Spain and Asia Minor. Italy dominated trade and Italian dyers had access to dyes that were not generally available in many other parts of Europe. The 14th century archives of  Francesco di Datini in Florence and Prato list lac (Kerria lacca), an insect dye from India and South-East Asia, and indigo (Indigofera tinctoria) from Baghdad among their items of trade.

 

During the Middle Ages dyeing flourished in Europe and it was the craft of the dyer that added most to the value of textile fabrics. Guilds of master dyers became established and a master dyer’s recipe book was closely guarded. The list of dyes and details of dyeing techniques found in dyers’ recipe books of the period indicate the increased complexity of some of the methods. The first known manual written for the professional dyer was the Plictho de larte de tentori, which was a collection of recipes for dyeing wool, silk, cotton and linen. It was compiled by Gioanventura Rosetti, Master of the Arsenal in Venice, and published in Venice in 1548. This manual is an important document in the history of dye chemistry and technology and clearly shows the stage of development that the dyer’s craft had reached by the middle of the 16th century.

Dyeing brown and grey wool fibres

Sunday, March 24th, 2013

 

In my new book I am focusing to some extent on native plants and fibres, so wool plays an important part – and not only white wool but also naturally-coloured wool. Recently I have been spinning naturally-coloured light brown and grey wool fleece and I love the effects when these skeins are dyed. The colours can be very subtle. Here are some examples:

 

dyes-on-grey1

 

From left to right: Madder, Indigo, Rhubarb Root

The first skein in each pair shows the dye colour on white wool and the second skein shows the dye colour on light grey wool.

 

All the skeins are unmordanted.

 

P1000464

 

The samples above are from horsetail (left) and tansy (right) and show from left to right: alum mordant on white wool, no mordant + alkaline modifier on brown wool , no mordant + alkaline modifier on grey wool

 

I find alkaline modifiers extremely useful, especially when used on fibres that have not been mordanted with alum. Even when the colour on the dyed fibres looks rather insipid initially, an alkaline modifier can often deepen and brighten it. The results of alkaline modifiers on naturally-pigmented wool are particularly pleasing, as I think the samples above show.