Archive for the ‘Dyeing Tips & Recipes’ Category

Good Old Onion Skins

Friday, February 12th, 2010

I haven’t used onion skins in the dyepot for several years, although I still always save them, and I keep the red onion skins separately from the brown ones, as they often give slightly different shades in the dyepot. Whilst rummaging through some of the boxes in my workshop recently, I unearthed several bags of onion skins, so last week I decided to use some of them to dye some skeins of wool.

Onion skins will dye quite readily without the use of a mordant but for the strongest, most vivid colours I use an alum mordant. However, if you use unmordanted fibres, the use of an alkaline modifier after dyeing will increase the depth and brilliance of the shades. For very deep colours you may need to use 100% weight of onion skins to weight of fibres, but I usually find that 50% gives sufficient depth and brilliance.

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Colours on wool from brown onion skins

 

 

 

 

 

I started off by using some brown onion skins. The above photo shows, from left to right: Alum mordant, alum + iron and, from the exhaust dyebath, alum mordant, alum + iron

I then made a dyebath using some red onion skins. In the past, I have sometimes achieved interesting green colours from red onion skins but this time the colours obtained were not as bright as I had hoped they would be, probably because I only had a handful of skins. The photo below shows from left to right: alum mordant, alum mordant + alkali, alum mordant + iron, no mordant, no mordant + alkali.

 

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Colours on wool from red onion skins

 

 

 

 

 

Afterwards, I wondered why it had taken me so long to get round to dyeing with onion skins again, as they really do give lovely colours, even if their light-fastness is limited.

P.S. to my Recent Woad Experiment

Thursday, November 19th, 2009

As a final experiment based on Leena’s method of making a vat with fresh woad leaves, I thought I would make two more vats, using unchopped woad leaves for one and chopped leaves for the other. I felt this should give an indication as to whether chopping the leaves increases the blue potential and, as usual, I set out with my own pig-headed opinion as to which would give the better results – chopped leaves, of course. After all, I always chop other fresh dyestuff into the smallest possible pieces, in the belief that the more surface areas there are, the more dye colour will leach out. Of course, the chemistry of indigo dyeing is quite different from that of dyeing with other plant materials, so it may well be that the advantages of chopping the dyestuff do not apply to woad leaves when dyeing blue.

To make sure the experiment had some validity, I used the same preparation and dyeing methods for each vat and I also used the same weight of leaves and skeins. I first simmered the leaves, chopped and unchopped, for a few minutes before steeping them for 15 minutes. I then added cold water to bring the temperature down to 50C and continued as described in my last post.

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This shows the two vats, after whisking to precipitate the indigo particles. The vat on the left was made using unchopped leaves and the one on the right was made using chopped leaves. There was very little difference between the two vats at this stage.

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This shows, on the left, the 4 skeins dyed in the vat made from unchopped leaves and, on the right, the 4 skeins dyed in the vat made from chopped leaves.

 The skeins were dipped in each vat for about 5 minutes each time and in the order in which they appear in the photo. So each vat was used four times and for one skein each time. The skeins dyed in the vat made from chopped leaves are very slightly deeper in colour but the difference in depth of blue is so tiny as to be barely noticeable.

So, contrary to my expectations, it would seem that chopping the leaves makes very little difference, if any, to the depth of blue achieved. That is certainly good news for those of us who like things to be as simple as possible. Now I suppose I should try my usual method, rather than Leena’s, using both chopped and unchopped leaves, to see whether similar conclusions can be drawn when using a slightly different method. But perhaps I’ll leave that test for next year.

A Woad Experiment

Friday, November 13th, 2009

I have been following Leena’s posts (www.riihivilla.com) about her experiences with using her home-grown woad leaves and I was particularly interested to learn about the method which gave her the best results. Although this method is very similar to the one I have been using for over 30 years, one element of it was new to me. I usually start by pouring boiling water over the chopped woad leaves and leaving them to steep for about 30 minutes.  I then strain off the liquid and squeeze the last drops of juice from the leaves before discarding them. I then allow the liquid to cool to 50C before adding the washing soda and whisking to introduce oxygen and precipitate the indigo dye particles.  However, Leena’s preferred method requires the whole unchopped leaves to be simmered in boiling water for about 3 minutes, after which the leaves are left to steep in the hot water for 15 minutes. The water is then strained off, the leaves removed and cold water added as necessary to reduce the temperature to 50C.

Leena’s recipe then proceeds much as the recipe I always follow. In both our methods, washing soda is added until the solution is around pH10 and then the liquid is whisked until blue froth forms. This whisking continues until the froth that is forming ceases to be blue and changes to white. Both methods then continue in exactly the same way, by adding the reducing agent and then using the vat once the liquid has changed in colour to greeny-yellow.

I decided to test each of these methods using the same quantity (400gms) of leaves for each, picked on the same day and grown under the same conditions. I left the leaves for Leena’s method unchopped but chopped the leaves for my method, as that is what I usually do. I then tested the two dye vats using the same weight of the same type of wool for each dip in each vat and leaving the wool in each vat for the same length of time. This ensured that each vat was used in the same way, so the experiment had some validity.

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This photo shows:

On the left: the blue froth formed following my method 

On the right: the blue froth formed following Leena’s method.

 

 

As the froth on the surface on the left seemed a much deeper blue, I was expecting to achieve deeper blues on the yarns dyed in this vat. So at this stage I was beginning to feel that my method might, after all, prove to be the better one. But “pride goes before a fall”!

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The three skeins on the left were dyed in the vat made following my method (“my vat”)and the three skeins on the right were dyed in the vat made following Leena’s method (“Leena’s vat”).

 

 So although “my vat” seemed to form froth a much deeper blue in colour than the froth on “Leena’s vat”, to my surprise this did not appear to influence the results when the skeins were dyed. In fact, the skeins dyed in “Leena’s vat” seemed a slightly deeper blue than those dyed in “my vat”. So my earlier expectations were proved wrong.

The question now is: which method will I follow in future? For workshop or demonstration purposes, I think my method is simpler because it doesn’t require a heat source and it gives perfectly good results. However, for my own purposes, I shall probably try out Leena’s method again, as it may enable me to get slightly deeper shades of blue. So my thanks to Leena for introducing me to a new and useful method.

Mulberry Bark

Friday, October 30th, 2009

Several weeks ago I was sent some mulberry bark by a kind lady who had collected some from a fallen branch from an ancient tree and thought I might like to try it out in the dyepot. As I’ve never tried mulberry bark before, I was interested to see what sort of colours it might give.

I started by leaving the bark to soak in water for a week or two and then I simmered it for about an hour, before adding some alum-mordanted and unmordanted wool fibres. I used about the same weight of fibres and bark and I kept the temperature just below a simmer, as the tannin in barks can sometimes dull the colour if the temperature is too high. When the fibres had taken up as much colour as possible, I turned off the heat and left them to soak overnight. I then applied alkaline and iron modifiers to some of the samples.

The photo below shows the colours I obtained.

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Left to right: No mordant, no mordant + washing soda, no mordant + iron, alum mordant, alum + washing soda, alum + iron

Some of the colours produced from the mulberry bark are more yellow in tone than the colours often obtained from barks and I was interested to see how little they reacted to the two modifiers I used. My thanks to Ann Machin for supplying the bark for this experiment.

Dyeing with Madder

Friday, August 28th, 2009

As I have some home-grown madder waiting to be processed, I thought I’d write a few more words about dyeing with madder. 

IMG_2098Madder in my dye garden

 

 

 

 

 

 

After the madder roots have been dug up (and remember to dig as deeply as possible so as not to miss the thickest roots), they need to be washed well to get rid of the soil. Although some sources suggest otherwise, the roots can successfully be used freshly-dug and straight from the ground and I have obtained excellent bright reds from fresh roots. They can also be dried for use later.

IMG_2406Madder roots dug up from the garden

 

 

 

 

 

 

I usually soak the roots in a tub of water for an hour or two and then scrub them with a brush to get rid of the dirt. As it’s a good idea to wash out some of the less desirable brown and yellow pigments, it doesn’t matter if some colour leaches out into the washing water. Once the roots are clean, I chop them up as small as possible. (Incidentally, a garden shredder or an old food-processor can be very useful for chopping up madder & other roots.)  If I don’t intend to use them immediately, I then spread the roots out to dry on sheets of newspaper on wire mesh or wooden trays or in shallow cardboard boxes. If I’m lucky and the sun is shining, they dry fairly quickly outside. Otherwise I put them in the airing cupboard. If you have to put the roots on top of one another, it’s a good idea to put a sheet of newspaper between the layers and make sure to turn them over regularly, so they don’t develop mould. Once they are completely dried out, I put them in strong paper sacks and store them in a dry place, either under a bed or in the airing cupboard. It’s important to keep them away from damp and wet, as they can easily become mouldy. It’s not too disastrous if they do develop mould as they still seem to produce a reasonable dyebath, although the colour may be duller.

To obtain a true red from madder it is necessary to use an alum mordant. However, madder can also be successfully applied to unmordanted fibres, especially wool. The colours obtained without a mordant tend to be more orange or brown in tone but using an alkaline modifier (for example washing soda) can often produce some very attractive shades of pink. An aubergine purple can also be obtained from madder by using iron as a mordant and then applying an alkaline modifer.

I’ve done many experiments with madder over the years, usually leaving the roots in the dyebath & either dyeing without heat at all or following the often-repeated instructions to keep the temperature low for reds. However, I discovered a little while ago that madder root can be simmered to extract the colour, just as one does with other dyes, without losing the red. Before I do anything else, I wash the roots in cool to warm water, then strain them through a sieve to get rid of the water. I then put the same roots in a pot & pour boiling water over them (at least enough to cover them well), leave them for a minute or two & then strain off the liquid, which can either be thrown away or used for a separate dyebath. This gets rid of some of the less desirable yellow & brown pigments. If I’m feeling really brave, I may repeat this last process once more, especially if I plan to save the discarded liquid for a separate dyebath, but I’m always afraid I may be removing some of the very desirable red dye, as well as the pigments I don’t want. Then I add more boiling water (or cool if you prefer not to keep boiling up the kettle) to the same madder roots & simmer them for about 30 minutes. I then strain off the dye liquid, let it cool to well below a simmer, add the fibres & leave them to steep for as long as it takes to get the red I want. I may add some heat after a while but I never allow the dyebath to simmer once the fibres have been added. This method seems to result in reds just as good as, and often better than, those from the more common madder-dyeing methods. And the roots can be simmered again for another dyebath.

If you live in a soft water area, your tap water may be too acidic to be able to achieve reds from madder and you will only get oranges and rusts. These shades can be shifted towards red by using an alkaline modifier, such as a washing soda after-bath. Washing soda can also be added to the prepared dyebath but only if you plan to apply the dye without heat. It’s important to remember not to apply heat to any solution containing washing soda, especially if you are dyeing wool, as this may destroy the fibres.

Madder is a truly remarkable dye & it is often difficult to completely exhaust the roots. I now often dry out the roots after the first dyeing process & store them ready to use again later. If you do this, don’t store the dried roots in plastic bags as they readily become mouldy if they get the least bit damp. (Actually, they still seem to be fine to use even if they are mouldy, although the dyebath smells less pleasant.) I dry the roots out in the airing cupboard as described above, then put them in paper sacks & store them in the airing cupboard or under a bed until I need them.

If you grow your own madder, don’t forget that the dried plant tops also give pretty colours. Around late Autumn, the plant tops start to look dry & pale, like straw, & they can be cut off & used for a dyebath. With an alum mordant, they can give pretty pinks & without a mordant they give beige to tan colours.

Note: There are full details for using madder in my new book “Colours from Nature” (Click on “My Books” on the home page for more information)

IMG_0438[1]A range of shades from madder

Buddleia

Friday, August 14th, 2009

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Those of us who have buddleia bushes in the garden tend to accumulate a great deal of pruned material, when the bushes need to be cut back.

I have used these prunings in the dyebath several times and achieved some pleasing results. This year I have already cut back one of my buddleia bushes and this time I decided to separate the dead flower heads from the leaves and stems to see which parts gave the most colour.

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This photo shows: On the left the results from the “dead flower heads only” dyebath and on the right the results from the “leaves and stems only” dyebath. In each set the top skein is unmordanted, the second skein is alum-mordanted and the third skein (also alum-mordanted) has been modified in iron.

I poured boiling water over the materials for each dyebath and left them to steep overnight. In the morning I simmered the dyebaths gently for about 45 minutes, then added the skeins. I left the plant materials in the dyepot for the unscientific reason that I was too lazy to look for my sieves to strain off the dye liquid. Yes, I know I should be ashamed of myself! In general, I usually strain off the dye liquid to avoid having unwanted plant pieces lurking among the dyed skeins. However, it doesn’t really matter whether the plant pieces remain in the dye pot or not, as long as the dye colour has been properly extracted. The notable exception to this generality is madder root, which most dyers prefer to leave in the dyepot, as it gives up its colour gradually at temperatures below a simmer. (More about madder dyeing to follow in a later post.) There will no doubt be other dyes that some dyers prefer to leave in the dyepot and the choice is really a personal one. Once the skeins had been added, I simmered gently for about 30 minutes then left the skeins to steep until the dyebath had cooled. I was interested to note that the unmordanted skeins took up almost as much colour as the alum-mordanted ones, although only light- and wash-fastness tests will show whether the dye is as fast on the unmordanted skeins.

The amount of colour available from the dead flower heads was surprising. In future I will probably continue to separate the plant parts and make two dyebaths, as this extends the colour range available.

Dyeing with Woad Seeds

Saturday, August 8th, 2009

Dyers who grow woad will often find they have far more woad seeds than they could possibly need for sowing themselves or passing on to other dyers.

Some years ago I did some tests using ripe purple/black woad seeds in the dyepot and I was intrigued by the results.

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                                                                                                             This rather dark image shows the page from my record book where I have the samples from this dyebath. The upper (1) of each pair of samples is unmordanted and the lower (2) is alum-mordanted. The seeds produced an attractive green on alum-mordanted wool, and a more yellow colour on unmordanted wool. Perhaps the most interesting sample was the one modified in clear vinegar (acidic), which produced a pale pink on unmordanted wool and a deeper pink colour on alum-mordanted wool. An alkaline modifier gave lighter yellowy greens, copper intensified the greens and iron produced greyish greens.

Woad seeds can be used in the same way as most other plant materials and I would suggest using at least the same weight of seeds as fibres (100%). Simmer the seeds for about 45 minutes to extract the colour, then strain off the dye liquid, add the fibres and simmer them for about 45 minutes to an hour, or until the colour is deep enough.

                                                                                                                                                                                  Recently I collected a bagful of woad seeds for a dyebath. This time about half of the seeds I used in the dyepot were not fully ripe and were still green in colour, rather than purple/black. The colours I obtained this time were less interesting, suggesting that it is advisable to allow the seeds to mature fully and become black before using them in the dyepot.

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From top to bottom the samples are: No modifier, + acidic modifier, + alkaline modifier, + iron modifier. For each category there are two samples: the upper one is unmordanted and the lower one is alum-mordanted. The shades are very similar to those achieved from the earlier dyebath using fully mature seeds, but considerably less intense.

Woad Fermentation Vat

Sunday, August 2nd, 2009

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I mentioned in the previous post that I’d tried a fermentation vat from Helen Melvin’s booklet on indigo and the above photos show the initial stages of the vat. (I think the difference in colour between the vats in the photos is because one photo was taken indoors and the other photo outside.) The recipe is for indigo powder but I used woad powder instead. I have to confess that indigo and woad fermentation vats present a challenge to me, as I’m not a naturally patient person and I tend to become over-impatient with vats that can take several days to come into order and require frequent tending. This particular vat uses yeast and molasses to induce fermentation and remove the oxygen from the vat, and washing soda as the source of alkali. The pH level needs to be checked regularly, as the fermentation tends to make the vat increasingly acidic. When this happens, more washing soda has to be added. The vat also has to be kept warm over several days and this can require ingenuity as, even in the hottest UK weather, the temperature can drop considerably at night. As keeping the vat on a hotplate seems an unnecessary use of electricity and the weather was fairly hot anyway, this time I placed the vat (in a lidded plastic container) inside the tray of a  plant propagator, before putting on the lid. At night, I brought the vat into the conservatory and kept it overnight in a container of hot water. (On reflection, it might have been better to have left the vat in the propagator and packed it round with polystyrene or straw to keep it warm, as the water became cool during the night.) After about two days the vat was usable and I managed to dye a skein of wool a reasonable shade of blue. (As I wasn’t sure how well the recipe would work and I didn’t want to waste my precious woad powder, I suspect I was rather mean with it and that meant the colour produced was not very deep.) I kept the vat active for another couple of days but by this time my patience was running low and the odour of the vat was beginning to be rather unpleasant, even to my less than delicate nostrils. So I decided it was time to pour the vat away. 

IMG_2308                                                                                       This shows some of the dyed skeins

So why bother with fermentation vats? This is a question I ask myself each time I make a fermentation vat. I think the answer is that it does me good to be presented with a challenge and to have the chance to appreciate how skilled the dyers of the past must have been. I have convenient pH papers, with which to check the pH value of the vat, but the dyers of the past had to rely on experience, appearance and taste. They knew exactly how and when to “feed” the vat to keep it active over a long period of time and when to allow it to rest. I think I regularly try out fermentation vats so that I can feel entitled to call myself a dyer.

Cochineal

Friday, July 3rd, 2009

My most recent use of cochineal was to dye some handspun Blue-faced Leicester fleece in readiness for my granddaughter’s winter coat. My daughter asked for a strong pink colour because she wants to make it clear that Milly is a girl and not a boy! Apparently too many kindly old ladies look at her and admire “such a sweet little boy” and this is beginning to cause my daughter, Jessica, stress. I keep telling her that babies and toddlers all tend to look like boys until they have enough hair to display their sex through a suitable hairstyle, but in the meantime my task is to produce garments that have a decidedly feminine bias!

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These colours should be feminine enough, I hope!  All the skeins were alum-mordanted and the first three were dyed using a cochineal extract from France. The next skein was from the first exhaust dyebath. For the last skein, I added a teaspoon of madder extract to the remaining exhaust dyebath and this livened up the shade a little.

To be honest, I shall be quite relieved when this desire for pink wanes because, as a vegetarian and supporter of female equality, I have to confess to a certain reluctance to use cochineal, unless I need a colour that can’t be achieved from any other dye. This reluctance is because the dye colour in cochineal is contained in the bodies of female scale insects of the Dactylopius species, which live on species of Opuntia or prickly-pear cactus, and many thousands of insects are required to make a relatively small amount of dye colour.

More about cochineal

The cochineal insect is probably native to Mexico but spread elsewhere in Central and South America. Today, Peru is the main producer of the dye and cochineal is also farmed in the Canary Islands, where it was introduced as a commercial crop in the 19th century.

Cochineal is a precious commodity and correspondingly expensive. However, a little goes a long way and full colours can be achieved using as little as 10% cochineal per weight of materials to be dyed, although the depth of colour may also depend on the chemical composition of the water used.

The shade of red for which cochineal probably became most famous is a brilliant scarlet, the colour of English huntsmen’s jackets. This colour was found, possibly by accident, in the early 17th century by a Dutch engineer and alchemist, Cornelius Drebbel, who discovered that the addition of tin to cochineal resulted in a brilliant red colour. Once dyers had mastered the use of tin in cochineal dyeing, this red colour was much in demand. It was used for British army officers’ uniforms and Gloucestershire became famous for scarlet woollens dyed with cochineal and tin.

This red can be re-created by the addition of 7% tin (stannous chloride) and 8% oxalic acid to the prepared cochineal dye bath and in the past I have successfully used it on unmordanted wool fibres. (See photo below.) Nowadays I prefer to avoid tin and the chemical oxalic acid, as they are among the more toxic chemicals and not really necessary for my purposes. But Drebbel’s Scarlet is certainly an amazingly brilliant shade of red.

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Drebbels’s Scarlet

Dyeing with cochineal

Cochineal is a versatile dye and gives light- and wash-fast shades of pink, red, orange, purple and purple-brown. Cochineal also reacts well to colour modifiers. An acidic modifier makes the colour more orange in tone, alkaline and copper modifiers shift the shades towards purple, and an iron modifier makes the colours purple-brown.

Dyers living in areas where the tap water is hard, rather than soft, sometimes report that they find it difficult to obtain strong colours from cochineal. One possible solution would be to use distilled water or rain water. Alternatively, water for the dyebath can be boiled and left to stand to allow any sediment to sink to the bottom. The water can then be carefully poured or siphoned off, without adding the sediment to the dyebath. The tap water in my area is hard, with a pH value of  7, which is neutral, so hardness may be more of a problem in areas where the pH value of the water is too alkaline (ie above pH8). If this is the case, reducing the pH of the water by adding a teaspoon or two of citric acid or cream of tartar might help. I sometimes add citric acid to the cochineal dyebath if the dyed colour appears too purple in tone and this shifts the colour towards red.

Many dyers use cochineal in powdered form – either purchased as a powder or ground in a mortar and pestle or a coffee-grinding machine. However, in my experience the powder particles can sometimes be very difficult to remove from the dyed fibres, unless the dye bath is strained through a coffee filter paper before use. The cochineal insects can also be used whole or partially ground and, if I am using whole insects rather than the extract form of cochineal, I use the multiple extraction method to extract the colour. This means that the cochineal dyestuff is simmered two or three times for about 15 to 20 minutes and each time the dye liquid is strained off into the dye pot. The combined liquids form the dye bath.

To start with, pour boiling water over the cochineal and leave it to steep for 20 to 30 minutes. Then add more water if necessary to ensure the liquid doesn’t boil dry and simmer the cochineal for 15 to 20 minutes. Then strain off the liquid through muslin or a fine-meshed sieve into the dye pot. Repeat this process twice more, using the same cochineal dyestuff. If you are using powdered cochineal, strain the dye liquid through a coffee filter paper each time and strain again before use. If any scum has formed on the surface, remove this with kitchen paper before using the dye bath.

Then add the fibres, plus more water if necessary to enable them to move freely in the liquid, raise the temperature gradually and simmer for 30 to 45 minutes. Leave to cool, preferably overnight, then rinse well and wash the fibres in a pH neutral washing medium. I usually use dishwashing liquid, which is ideal for washing dyed materials.

Cochineal is also readily available as an extract and in this form it can simply be dissolved in hot water and then added to the dyebath. Half a teaspoon of dye extract will usually dye 100gms of fibre a rich shade. The fibres are then added and dyeing proceeds as described above.

Pinks and reds

An alum mordant produces shades of pink and pinkish red on all fibres. For pale pinks use 5% cochineal (i.e. 5gms cochineal per 100gms dry weight of fibres) and for deeper shades increase the amount to between 15% and 30%, depending on the depth of colour required. Prepare and use the dye bath as described above.

In Peru, where chemical mordants may be difficult to obtain, cochineal is sometimes used without a mordant on animal fibres. The following method will give a rich tomato-red if the right amount of acid is added. Use 20% to 30% cochineal and prepare the dye bath as described above. Then gradually add drops of either clear vinegar or lemon or lime juice, stirring well as you proceed, until the liquid is a bright red-orange in colour. Be careful not to add too much acid, or you will miss the red and end up with orange. If you add too little, the fibres will be too brown in tone. Stir well again, then add the unmordanted fibres and continue as described above. If necessary, soak the fibres after dyeing for 15 to 30 minutes in a weak solution of water and clear vinegar to brighten the colour.

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This photo shows a range of shades from cochineal

Indigo Rub-off

Monday, May 18th, 2009

Recently I was looking through The Mulberry Dyer Debbie Bamford’s blog (http://colourextractor.blogspot.com/)  and read about the problem of rub-off from indigo-dyed yarns. I should add that Debbie was not experiencing the problem herself but had come across the comment in another blog. Debbie used this comment as an example of how poor dyeing techniques can harm the reputation of natural dyeing, leading to the belief that problems such as rub-off or fading are only to be expected from natural dyes. Like Debbie, I feel situations like this are a great shame, especially as natural dyes, when properly selected and applied, are as reliable as synthetic dyes, if not more so.

It can be very irritating to find one’s fingers becoming blue as one uses indigo-dyed yarn. In my experience there are two main reasons why this rub-off may happen. The first reason is that the yarns were not properly cleaned before dyeing, so the dye becomes attached to the dirt or grease, rather than to the fibres, and is then rubbed off as soon as the yarns are subjected to any friction. The other reason is that the yarns were allowed to dry before being rinsed. When indigo-dyed materials are aired, it is important to turn them round from time to time, so no sections dry out before the fibres are rinsed. This is because any loosely-attached indigo becomes more firmly attached once dried and is not removed by rinsing or washing. However, it will come off when used in any way that causes friction.

There are other precautionary measures I routinely take. Firstly, as soon as I take materials out of the indigo vat, I plunge them into a bucket of clear water and move them around under the surface for about 30 seconds to a minute. This removes some of the indigo that may be loosely attached to the fibres. As water contains oxygen, it is also possible to leave the fibres to oxidise in this clear water, although they must remain below the surface and it will take longer for the fibres to turn blue. In fact, if patchy indigo dyeing is a problem, this is one way of avoiding it. Also, after airing them, I usually put indigo-dyed materials through a washing-machine rinse cycle whenever possible. Of course, this can cause skeins to become hopelessly tangled if care is not taken, so to prevent this, I tie skeins firmly in a bag or pillow-case before rinsing them.

Whatever our preferred dyeing methods and techniques may be, I firmly believe that, as dyers, we are responsible for the reputation of natural dyes and it is up to us to make sure any naturally-dyed items offered for sale, or as gifts, meet the highest possible standards. Anyway, lecture over now!