Archive for the ‘Dyeing Tips & Recipes’ Category

1-2-3 Indigo Fructose/Lime vat

Sunday, February 19th, 2012

I have read several times about Michel Garcia’s indigo vats – in reports from the ISEND natural dye conference in France, in posts on Helen Melvin’s blog and most recently in an article by Jane Deane in The Journal for Weavers, Spinners and Dyers. Michel Garcia is a bio-chemist who has been researching indigo dyeing for many years and he has developed indigo vats that are simple to make and ready to use in a short space of time. Michel wants his environmentally-friendly methods to reach as many dyers as possible, so I decided to try out one of his recipes and then pass on the information, so others can use it too.

The vat I have tried is his 1-2-3 vat, so called because of the proportions of the ingredients used: 1 part indigo, 2 parts slaked lime (calcium hydroxide) and 3 parts fructose. This means that for 10gm indigo you would need 20gm calcium hydroxide and 30gm fructose, for 20gm indigo you would need 40gm calcium hydroxide and 60gm fructose and so on. Calcium hydroxide or slaked lime should be available from builders’ merchants but I bought mine on the internet from Amazon. I purchased fructose from our local health food shop but it may also be available in some supermarkets. For my  trial vat I used 1 teaspoon indigo powder, 2 teaspoons calcium hydroxide and 3 teaspoons fructose.

NB Calcium hydroxide should be handled with caution. It can irritate skin and lungs and cause serious injury if it comes into contact with the eyes. Do not pour water onto it but add it slowly to water.

To make the vat, start by putting hot water (around 40C to 50C but no hotter) in a dye pot or heatproof strong glass jar. Mix the indigo powder with hot water to make a smooth paste and make sure no gritty particles remain unmixed. (Jane Deane’s article gave a useful tip for mixing this indigo paste: put the powder and water in a small container with a well-fitting lid and add some marbles (or marble-sized smooth stones). Then shake vigorously to incorporate all the indigo particles in the solution. I’ve tried this and the marbles really help to make a smooth paste.)

Add this indigo solution to the hot water in the vat or jar, then stir in the calcium hydroxide. Finally add the fructose and stir well. The vat may take up to 45 minutes to be ready but mine was ready to use in about 5 minutes. The vat can then be used in the same way as other indigo vats. One recommendation was to add the fibres dry, rather than wetting them first, but I forgot this and wetted out my wool skein automatically, as I usually do, and it didn’t appear to matter. I suspect this recommendation probably refers mainly to cotton and silk fabrics, which I often add dry to indigo vats anyway. Another suggestion was that the pH of this vat might be too high for wool. However, my vat was pH11 but I dyed wool in it without any obvious ill effects. The wool remained in the vat for about 30 minutes and dyed to a mid-blue; further dips didn’t increase the depth of blue. I also added some silk fabric and a cotton skein to the vat and both dyed to a similar shade of blue as the wool. Jane Deane’s article implies that this vat is likely to produce only pale to mid blues but the lack of a deep blue from my vat may have been because I only used 1 teaspoon of indigo to make this trial vat. Anyway, I shall experiment further with this method and see whether deep blues can be achieved.

I found this method of indigo dyeing extremely simple and effective and, if it also dyes deep blues, it could be very useful.

This shows the vat with the ingredients added

This shows the vat ready to use

This shows the wool skein in the vat

This shows the skein on removal from the vat

This shows the dyed wool skein

Dyeing with Hedge Bedstraw

Wednesday, February 1st, 2012

I have been keen to experiment again with the native bedstraws but, since we moved house and I left my precious dye garden behind, I have been finding it difficult to harvest suitable bedstraw roots. The roots of the Lady’s Bedstraw (Galium verum) plants that I have planted in my new garden are too immature and it is against the law to uproot plants in the wild, so it seemed that any experiments might have to wait a year or two for my own plants to be ready to harvest.

However, thanks to the generosity of Leena Riihela in Finland ( who kindly sent me some roots from her own garden, I have been able to experiment with Hedge Bedstraw, (Galium mollugo).

Compared with the roots of madder (Rubia tinctorum), bedstraw roots are very fine and delicate, and these bedstraw roots were very precious as they had come from such a long way away. So I wanted to make sure that I didn’t waste them.

For these tests I used mainly alum-mordanted wool, except for some unmordanted samples from the exhaust dyebaths. To prepare the dyebaths, I first soaked the roots overnight in water, then poured off this liquid. I then steeped the roots twice in boiling water for about 1 minute each time and added this liquid to the soaking water to make the first dyebath. I then simmered the roots twice more, using each simmering liquid for a separate dyebath. In the photos below, the orange colours on the left were from the soaking water plus the two steeping waters and also from the first 2 simmerings. I then simmered the roots again twice for about 45 minutes and used this liquid for another 2 dyebaths. The middle range of shades on the photos were from these 3rd and 4th simmerings, the redder one with an alkaline modifier (washing soda). The range on the right came from exhaust dye baths, with some unmordanted and some alum-mordanted samples. Once the fibres had been added to the dyebath, I didn’t worry too much about the temperature and allowed the dyebaths to simmer gently to improve colour take-up. (This simmering is not something I would do when dyeing with madder – see below)

I decided to work in this way, rather than combining all the extractions, because my belief is that the richest true reds lie under the yellows and browns and the best way to get reds is to first use up these yellows and browns. I don’t know whether this belief is correct but my experiences suggest it seems a good way to get reds rather than oranges. 

I now use this method when dyeing with madder and it seems to work well. After washing the madder roots well, I simmer them to extract the colour for the first dyebath, remove the roots to use again for a second dyebath and then reduce the temperature before adding the fibres.  Once the fibres have been added, I don’t simmer the madder dyebath and I keep the temperature hot but not too hot – i.e. well below simmering point. The roots can then be simmered again to extract more colour for a second dyebath. Indeed, madder is a most generous dye and the roots can often be simmered several times before the dye is exhausted, giving colour for yet more dyebaths.

I think that, when I next dye with the bedstraws, I will probably keep things simpler and try something closer to the method I use with madder. So, after soaking the roots overnight,  I will simmer them once for about 30 minutes and use this solution for my first dyebath. I will then simmer the roots again (probably for about 45 minutes) for a second dyebath and to make sure no precious dye is wasted, I will simmer the roots at least once more for a further dyebath. But first I must wait for my bedstraw roots to be mature enough to harvest.

A range of shades from Hedge Bedstraw (Galium mollugo)

A close-up image of some of  the Hedge Bedstraw colours.

Making and Using an Indigo Stock Solution

Sunday, November 6th, 2011

Thanks to Helen Melvin’s booklet on indigo dyeing, “The Colour of Sea and Sky”, and Helen’s comments on the merits of making an indigo stock solution, I decided to experiment again with this method of making an indigo vat. This was the method I first used with indigo over 30 years ago and Helen’s book reminded me of the advantages of the stock solution method, among them the fact that indigo reduces more efficiently in a concentrated alkaline solution and there is therefore less likelihood of wasted, undissolved indigo. Also, using a stock solution means that the colour can be built up relatively easily.

So why did I stop using the stock solution method? The main reason is that the one-step-bath method I generally use now, and which appears in my books, is more practical for one-day workshops, as the vat is quick to make and this enables me to demonstrate how to make and use an indigo vat in a short space of time. However, after we have used this vat there is often some indigo remaining, which gets thrown away, (unless students can take some solution home with them). Indeed, I often tell students that this vat is even better on the second day, as the indigo has had more time to reduce completely. The other reason for abandoning the stock solution method is my desire to avoid the use of caustic soda, which can cause bad burns if not used with great care.

Helen’s stock solution recipe is quite simple and involves mixing 50gms of indigo powder with 2 tablespoons each of caustic soda (the alkali) and thiourea dioxide (the reducing agent).

For my stock solution I used sodium hydrosulphite (hydros) as the reducing agent and this also works perfectly. I first mixed the indigo powder to a smooth paste in 4 tablespoons of very hot water in a large heatproof jar. I then topped this up with hot water but no hotter than 50C, which is about as hot as a hand can tolerate. (NOTE: Don’t fill the jar too full and leave enough space for any bubbling or fizzing that may occur.) Then I very gently stirred two tablespoons of caustic soda into this solution, followed by two tablespoons of sodium hydrosulphite (or use thiourea dioxide instead of hydros). This is the stock solution. NB Remember to wear rubber gloves and bear in mind that both caustic soda and the reducing agent should be added carefully to water and never pour water directly onto them.

Keep the jar warm and after about 45 minutes the stock solution mixture will become a clear amber colour, although the surface, which is in contact with oxygen from the air, will be a dark blue colour with a lustrous sheen. The stock solution is now ready to use.

To make the vat, fill the container up with water no hotter than 50C, add a teaspoon of hydros (or alternative reducing agent) and a teaspoon of washing soda and allow to stand for a few minutes. Then gently stir in one or more tablespoons of stock solution, according to the size of the vat and the depth of blue required. The vat can then be used as usual and more indigo stock solution can be added as necessary.

Further information on making and using a stock solution and many more recipes can be found in Helen’s booklet “The Colour of Sea and Sky”, which I highly recommend. And of course, like all Helen’s books, it has a lovely hand-painted cover.

The photo below shows a range of blues from indigo

Ice Flowers

Tuesday, September 20th, 2011

Another interesting technique from India Flint's book "Eco Colour" is what she calls "ice-flowers". This involves the collection of purple and deep red flower petals (which contain anthocyanins), which are then frozen in plastic containers or sealed plastic freezer bags for at least two days. Following India's instructions, I collected the dead-heads from purple violas over a period of several weeks and froze each batch of flower heads as soon as I had collected them, adding them to the plastic bag in the freezer. When I was ready to use them, I tied a handful of frozen flower heads into a muslin bag, immersed this bag in lukewarm water and squeezed it to extract the colour. The liquid soon became a rich purple colour and I removed the bag with the flowers and then stirred a teaspoonful of alum sulphate into the solution. (I added alum because the materials I intended to dye had not been mordanted. Next time I try this method I'll make sure I have some pre-mordanted fibres ready to use.) I then put some cotton and silk fibres into the liquid and left them to steep overnight.  More colour variations are possible if other substances, such as an acid or an alkali, are added to the solution, so I still have much scope for experimentation. (I later added a wool skein to the exhaust dye bath and this became an attractive light leafy green.)

The photos below show, from the top: the frozen viola flowers ready for colour extraction, the dyed materials (silk on the left and cotton on the right)), a closer view of the dyed silk fabric, and finally a closer view of the dyed cotton fabric. The dyed skein is cotton and the dyed cotton fabric is the bag in which the flowers were tied. The attractive variegated colour effects on this bag are probably the result of the flowers being pressed against the fabric. As with the leaf prints, I must test these ice-flower dyes for light- and wash-fastness, once the colours have had time to mature.




Leaf Prints

Tuesday, September 13th, 2011

Recently I was inspired by India Flint’s book “Eco Colour” to experiment with leaf prints. India’s book contains a wealth of ideas and is full of beautiful images of her printed fabrics. This fascinating technique has become very popular among dyers and can have really lovely results.

I collected some leaves from my garden, mainly from a eucalyptus tree and a Judas tree (Cercis siliquastrum), and used cotton and silk fabrics mordanted with alum. (I decided to pre-mordant the fabrics to improve the fastness of the colours.) I placed the leaves on the wetted cotton fabric, added a few rusty nails, put the silk fabric on top of the cotton fabric and then carefully folded the fabrics into a bundle, which I tied with string. I decided to put this bundle into the compost bin my husband uses for grass clippings, as it can get quite hot in there and this therefore seemed a useful way of setting the dyes.  After four days, I removed the bundle to reveal the results below. Now I need to do some light- and wash-fastness tests to see how fast the colours achieved from this method will be.

The first photo shows a section of the cotton fabric and the second photo shows a section of the silk fabric.



Anglo-Saxon dyes – woad

Saturday, August 27th, 2011

Woad (Isatis tinctoria) was the Anglo-Saxon source of indigo blue. Although woad is not a true native plant (i.e. it was not present here before the formation of the English Channel), it is thought that it was introduced in the neolithic age when farming began. Some of the earliest textile fragments show evidence of having been dyed with woad and it was probably one of the first dyes to be used. As extracting blue from the indigo-bearing plants is somewhat more complicated than the method of extracting colour from most other plants, it may seem strange that blue was among the first dye colours. However, the indigo-bearing plants, including woad, were generally considered to have healing properties and it may be that their use as dyes developed from their use medicinally. For example, if woad leaves were applied to damaged skin as a poultice, perhaps together with urine, which was regarded as an antiseptic, the conditions necessary for extracting blue from the leaves might have developed. These conditions would be heat (from the skin) an alkaline medium (from the urine as it became stale) and bacteria from the urine. So one can imagine that, if the poultice was removed to reveal blue skin beneath it, people would have been able to work out how to use the leaves to dye textile fibres. Another possible scenario might occur if woollen fleece was being cleaned in a tub of urine and someone dropped woad leaves into the tub by mistake. The woad leaves might remain in the tub long enough for the urine to act on them and could, in effect, create a woad vat in the tub. When removed, the fleece would become blue on contact with the air. Once people noticed the presence of the woad leaves in the tub, they would probably have been able to work out why the fleece had become blue. All this is purely speculation, of course. Woad vats would have been organic in the Anglo-Saxon period and might have been made using stale urine, which provides both the source of alkali and the bacteria needed to make the vat active.  Woad leaves may have been harvested and used fresh or they may have been allowed to ferment and processed into woad balls and stored for later use. Another method of dyeing with woad may have been the fermentation vat, made using wood-ash water as the source of alkali and madder and bran to induce fermentation and remove the oxygen from the vat. The recipes for these vats can be found in "Colours from Nature". The first photo below shows pale blue shades from woad. In the second photo the first three skeins show a range of shades from a woad fermentation vat. (The other skeins show lichen purple and black achieved by dyeing.


Anglo-Saxon dyes – lichen purple

Tuesday, August 9th, 2011

Lichens of the species Ochrolechia and Umbilicaria give beautiful brilliant purple and red shades when treated in stale urine or a solution of water and ammonia and no mordant is required for these dyes. This purple colour seems to have been used relatively rarely by the Anglo-Saxons, probably because the lichens needed to produce it only occur in restricted regions of Britain, mainly in the North and West in hilly areas or rocky, coastal districts

Analysis of the dyes used in textiles from the early Anglo-Saxon period shows that purples from lichens were used in embroidery, narrow woven bands and accessories, such as bags and headdresses, rather than to dye larger fabrics. Bearing in mind the scarcity of purple-producing lichens in southern and eastern England, this is perhaps not surprising.



This photo gives some indication of the beautiful purples available from lichens but does not do justice to the brilliance of these colours, which sadly are not very lightfast.




I do not recommend using lichens for dyeing, except in very small test dyebaths, as lichens grow very slowly and may take a long time to regenerate. Lichens should never be harvested indiscriminately and some may be protected species and should never be gathered. It is very important to be sure you have correctly identified each lichen before even considering collecting any. However, even a small piece of lichen the size of a large coin can yield enough purple dye for most test purposes.

Purple-producing lichens are prepared by soaking them in stale urine or in a solution of 2 parts water to 1 part ammonia. Use a strong glass jar with a  well-fitting lid and shake or stir the solution every day. It can take several weeks for the purple colour to develop. When the solution is a rich purple in colour, strain off the liquid into a dye pot and add the fibres to be dyed, plus more water if necessary. If you have used ammonia, make sure not to inhale any of the rather unpleasant fumes. (Stale urine can be equally unpleasant, of course!) Then heat the solution gently to simmering point and simmer gently for about 30 minutes. Take great care when heating the solution, as ammonia can catch fire very easily. Then allow the fibres to steep in the solution overnight. Then remove the fibres, squeeze the excess liquid back into the pot and re-use the solution until it is exhausted.

If the dyed fibres are steeped in an acidic modifier (for example in a solution of clear vinegar and water) they will become redder in tone. Using an alkaline modifier, such as wood-ash-water, will make the fibres more purple in tone.

The 4th skein from the left in the photo below shows some of the variations from acid and alkaline modifiers.




Indigo workshop

Sunday, July 3rd, 2011

It was a pleasure to return in June to the Bedfordshire Guild of Weavers, Spinners and Dyers, of which I was a member for over thirty years before we moved to West Sussex. The occasion was an indigo workshop I was leading and I was delighted to see old friends and to meet some new members.

To demonstrate the various sources of indigo dye, I made several vats using natural indigo, synthetic indigo, woad leaves, woad balls and stored woad solution.

I used the Colour Run Remover recipe given in my books with the synthetic indigo. However, as Colour Run Remover is not always easy to find in powder form (the liquid form isn’t suitable for indigo vats), I decided to try a different method with natural indigo. I was looking for a simple method and, after some experimentation, it seemed that using equal quantities of indigo powder, washing soda and sodium hydrosulphite (hydros) would work well. An added advantage is that using equal amounts of each ingredient makes this a very simple recipe. As indigo reduces better in a more concentrated solution, I decided to make a stock solution on the day before the workshop. To do this, I mixed 4 teaspoons of natural indigo powder with very hot water to make a paste. Then I dissolved 4 teaspoons of washing soda in very hot water in a strong glass jar, added the indigo paste and stirred well. I added more hot water until the glass jar was just over three-quarters full then, after checking that the temperature was not above 50C, I carefully stirred in 4 teaspoons of hydros and put the lid on the jar. I then placed the jar in a saucepan of very hot water and put this on a hotplate overnight. In the morning I checked the pH and added more washing soda to bring it to pH9. The solution looked a murky greenish yellow at this stage. When I arrived at the workshop, I filled a stainless steel bucket with very hot water (but no hotter than 50C) and added 2 teaspoons of washing soda and two teaspoons of hydros. I then gently added the contents of the glass jar. The vat was allowed to stand for about 20 minutes until the liquid below the surface was a clear greeny/yellow. (If this seems to be taking too long, add some more hydros.) This vat is very simple to make and worked well. However, I intend to experiment further to see if I can improve on this method.

Both of the indigo vats produced dark blues immediately and those students who wanted paler blues had to wait until some of the blue had been used before dyeing their samples. I also suggested that the wool samples should be dyed first, while the vats were hot, and that the cotton and silk samples should be dyed later, when the vats had cooled down. This is because wool takes up the indigo dye better in a hot solution, while cotton and linen prefer cooler solutions.

With the woad balls I used the recipe given in the revised edition of  “Wild Colour” and also in an earlier post on this blog. Unfortunately, the woad balls only produced a pale blue and not enough for all the workshop participants to dye their samples. I think the balls probably needed to steep for a longer period than we had available. We also had limited success with the fresh woad leaves, which gave very little colour. However, I suppose this was to be expected, as June is really too early to harvest the first year leaves, which hadn’t had enough time to develop their colouring potential. The woad solution, which gave deep to mid blues, was from 2008 and worked very well, so this proves (if proof is necessary) that correctly-prepared woad solution can be stored successfully for several years. The recipes I used for these two woad vats were those in my books.

The photos below show some of the materials dyed by students at the workshop.



Dyeing Cotton and other Cellulose Fibres

Monday, January 31st, 2011

As I have recently been working on an article for “The Journal for Weavers, Spinners & Dyers” on using natural dyes on vegetable fibres, I thought I’d write a few words on the subject here.

 There seems to be a fairly common belief that dyeing cotton and other cellulose fibres with natural dyes is often less successful than dyeing animal fibres, such as wool. This may be because some dyers use the same mordanting methods for all fibres, rather than selecting methods appropriate to each fibre type, and this can lead to disappointing results. However, using natural dyes on cellulose fibres has become simpler and less labour-intensive since aluminium acetate is now more widely available in the UK. Before the arrival of alum acetate, the alum-mordanting method generally used for best results when dyeing cotton or linen has probably been the 3-step tannin/alum/alum (or alum/tannin/alum) method, which takes several days to complete. This involves treating the fibres in sequence with both tannin and alum sulphate, the latter plus washing soda. Some dyers favour completing the tannin process first, followed by two treatments with alum and washing soda, while others prefer to carry out the tannin process between the two alum treatments. I don’t think it really matters which sequence one chooses.  Some dyers may opt to use only the alum sulphate plus washing soda step and to omit the tannin process completely, although in my experience this tends to give less satisfactory results, unless the cellulose fibres being treated have a natural tannin content, as may be the case with raffia. (See my earlier post: “A Natural Dyeing Project in Uganda”)

Detailed recipes for mordanting vegetable fibres are given in my books, so I won’t repeat them here. However, I would suggest that dyers who haven’t yet tried alum acetate as a mordant for cellulose fibres might find it worth while experimenting with the following mordanting recipe:

Use 5% alum acetate (or 2.5 tsps per 100gms/4ozs dry weight of fibres). Dissolve the alum acetate in boiling water and add this to cool water in the pot, stirring well. Then add the wetted fibres, plus more water if necessary to allow them to move freely in the solution, heat to simmering point and hold at this temperature for one hour. Then turn off the heat, leave the fibres to cool, preferably overnight, and then remove them and rinse them well. (Note: alum acetate is available from some of the suppliers listed on my blog under “Useful Websites”)

I have found this mordanting  method gives good results on cotton and other vegetable fibres. It is also suitable for silk, but not for other animal fibres, and is widely used in Japan as a mordant for silk. I used it to mordant fine silk fibres when dyeing silk for handweaver Maggie Stearn and found it most successful. (See my earlier post: “Maggie Stearn – Handweaver”)

Naturally-dyed cotton mordanted with alum acetate. Clockwise from left to right: indigo, brazilwood, weld, weld + indigo, fustic, madder, logwood, cochineal

Naturally-dyed cotton mordanted with alum acetate. Clockwise from left to right: indigo, brazilwood, weld, weld + indigo, fustic, madder, logwood, cochineal

Some of the naturally-dyed raffia fibres, dyed by the basketweavers of Rubona, Uganda.

Some of the naturally-dyed raffia fibres dyed by the basketweavers of Rubona, Uganda.

Fresh Walnut Hulls

Tuesday, December 14th, 2010

I suspect I am not alone in sometimes finding it difficult to achieve a really deep brown from walnut hulls. However, one solution to this problem is to use fresh green walnut hulls, rather than dried brown ones. This Autumn I was lucky enough to harvest some walnuts and, after eating the nuts, I saved the green hulls to use for dyeing. I left the hulls until they had started to become brown before I simmered them until the liquid was deep brown in colour. I then strained off the liquid, added some unmordanted wool skeins and simmered them for about an hour. I left them to steep in the cooling dyebath overnight before rinsing and washing them.

As can be seen from the first two skeins in the photo below, this dyebath gave a rich deep brown and the exhaust dyebath gave a paler shade. Now I just have to find a reliable source of fresh walnuts each year. However, I should be able to use these hulls for a year or two, as I always save the used hulls, plus their liquid, to use again and again. Don’t worry if mould forms as time passes – this will only improve the dye.

I also made a dyebath from fresh walnut leaves, which gave paler browns. (See the last two skeins in the photo below.)
Fresh green walnuts

Fresh green walnuts

Walnut leaves

Walnut leaves

The walnut hulls simmering to make the dyebath

The walnut hulls simmering to make the dyebath

Skeins dyed in the walnut dyebath

From the left, skeins 1 and 2 were dyed using fresh walnut hulls and skeins 3 and 4 were dyed using fresh walnut leaves