More from the Ditchling Museum natural dyeing course

We have now reached the stage in the course when we start on the adjective dyes, for which a mordant is used. The mordant most commonly used is aluminium sulphate (for animal/protein fibres) or aluminium acetate (for vegetable/cellulose fibres). We also dyed some samples using as a mordant symplocos from the dried leaves of trees of the symplocos species. (Full information can be found here in the blog posts Symplocos leaves as a source of aluminium mordant and More about Symplocos leaves as a mordant.) Symplocos trees are aluminium accumulators and absorb aluminium from the ground in which they grow. This means that the dried leaves are a plant alternative to the manufactured aluminium mordants. Symplocos mordant is currently only available in the US (from Botanical Colors) and Canada (from Maiwa Handprints) although it has also been available in France in the past.

The animal fibres (wool and silk) were mordanted using 10% aluminium sulphate and we used 5% aluminium acetate as the mordant for the vegetable fibres (cotton and linen). We didn’t apply a tannin mordant before the aluminium acetate as, although the tannin step is necessary if using aluminium sulphate on vegetable fibres, aluminium acetate can be used without the tannin step.

The fibres for some dyes were also mordanted with symplocos, so we would be able to compare the results from the two mordanting methods.

For all the tests described below we separated the animal and vegetable fibres, using a separate pot for each fibre category. The reasons for this are as follows: animal fibres tend to absorb dye more readily than vegetable fibres so, if both fibre types are in the same pot, the animal fibres may use up too much of the colour before the vegetable fibres have had a chance to absorb their share of the dye. Also, sometimes, depending on the dye, one fibre type may respond better at lower temperatures and using two pots means the heat level can be adjusted according to the needs of the fibre type.

At the first session we used 100% madder root (Rubia tinctorum), 100% weld (Reseda luteola) and 20% cochineal (Dactylopius coccus) in the form of dried beetles which were not ground into powder. (Incidentally, I never use dyes like madder and cochineal in powder form, unless they are powdered extracts which dissolve in water, as it can be very difficult to remove the tiny particles from the fibres. Also, most dyestuffs can be simmered a second time to extract more colour, but this is more difficult with powders.) All the dyes were put into cotton bags so there would be no need to strain off the dye bath, as the bag of dye could just be removed once the colour had been extracted. (To allow the dyestuff to give more colour to the dye bath, the bag of dye could also be left in the dye pot.)

Note: In workshop conditions, time doesn’t always allow for best practice and dyeing times may have to be shortened. However, it is important not to shorten the dyeing time too much, as this may also reduce the colour fastness. If the dyed colour appears deep enough after 5 to 10 minutes in the dye pot, remove the fibres, pour off most of the dye solution, fill the dye pot up with hot water and then return the dyed fibres. Simmer the fibres in this weakened dye solution for a further 20 to 25 minutes before removing them. For maximum colour fastness the fibres should remain in the dye bath for at least 30 minutes and ideally longer. It is also good practice to allow the fibres to cool in the dye bath and I often leave them to steep overnight. Finally, if the colour was deep enough after only 5 to 10 minutes in the dye bath, make a note to reduce the percentage of dyestuff used in future.


There are several ways of using madder and I am still undecided as to which method gives the best results. In the past I washed the madder first then poured boiling water over it, left it to steep for about a minute, then poured this solution off. I repeated this once more, added the second pour-off to the first and left the solution on one side to make a dye bath later. I then simmered the same madder pieces for about 30 minutes to extract the colour for the dye bath. However, for the experiments described here the madder root was first rinsed well under the cold tap to remove some of the brown and yellow pigments, then it was simmered for about 30 minutes to extract the colour. We also added 2 teaspoons of chalk (calcium carbonate) to brighten the colour. We allowed the dye bath to cool slightly and then the fibres were added and left to steep for about 45 minutes. As madder tends to continue releasing colour over a period of time, we left the bag of madder dyestuff in the pot during dyeing.

In my experience, madder can safely be simmered to extract the colour but it may be advisable to keep the heat below a simmer during dyeing, especially when dyeing wool or silk on an alum mordant. Maintaining this lower temperature seems less important for vegetable fibres and I have sometimes found that even simmering wool and silk fibres can give good reds. I also add a couple of teaspoons of chalk (calcium carbonate) to brighten the colour and I have read that adding cream of tartar to madder dye baths when dyeing silk can make the colour redder and less orange. However, I have not yet tried the latter. Some dyers add bran to the dye bath and although I have done this on occasion, I am not entirely sure why this is done. If bran is added, it must be tied into a bag, as it can be extremely difficult to remove from the fibres. On the whole, much seems to depend on the quality of the madder root and I have generally found that the browner the colour of the root before use, the less red the dyed colour may be. However, having said that, browner madder root can sometimes give equally good reds, so much is probably also luck.

Madder on cotton and linen fabrics

Madder on different types of paper

Madder samples dyed by Jacqui Symons From left to right: no modifier, +acid, +alkali, +copper, +iron

(Photos of full madder samples on four fibres available later)


The weld was simmered for about 30 minutes to extract the colour. Then the fibres were added and simmered gently for about 30 minutes. The temperature was kept a little below boiling point, as a slightly lower temperature often makes the colours from weld brighter and clearer.

  Left to right: no modifier, +acid, +alkali, +copper, +iron                                                                                                               Fabrics from left: linen, cotton, silk

Close-up of above image


The colour was extracted from the cochineal following the multiple extraction method. This means the cochineal was simmered three times and after each simmering the dye liquid was poured off into the dye pot. The three pour-offs formed the dye bath.The fibres were added and simmered for about 30 minutes.

Samples as above for weld (Fabrics from left: linen, cotton, silk)

  Samples as above for weld


Further samples were produced by individual students, some to be shared between all the students.

Ivy (Hedera helix) leaves (top) and ivy berries (below) Dyed by Lizzie Kimbley                                                                        Alum mordant and the usual modifiers in the usual (alphabetical) order


Fustic (Morus tinctoria), alum mordant  Samples (as for weld) Dyed for the group by Claire Bessel

Note: The results from the fustic were more mustard in tone than I had expected and Claire also asked about this, as she had followed the usual methods for dyeing. When I gave her the dyestuff I noticed it looked rather more brown than is usual with fustic and I think this probably influenced the colour. Also, we used 100% dyestuff and a lower percentage might have resulted in more yellow tones.

All photos by Zuzana Krskova

More from the natural dyeing course at Ditchling Museum of Art and Craft

This session was the last for substantive dyes and we used alkanet root, pomegranate peel and cutch (all without a mordant), with the usual four modifiers.

Although substantive dyes will fix without a mordant, the use of an aluminium mordant often gives different results because the alum attracts other pigments which may be present, particularly the flavonoids or yellow pigments. So cutch used with an alum mordant tends to give yellower shades than cutch used without a mordant and with an alum mordant walnut leaves often give yellows but they give tans and browns if used without a mordant. Be aware, too, that using an alum mordant will not necessarily improve fastness. In tests conducted by Gill Dalby, walnut leaves used on an alum mordant had lower fastness than walnut leaves used without a mordant.

This time I tried a different method with the alkanet root, which I soaked in vodka for 3 days before the workshop. This is because the red pigment in alkanet root is not soluble in water but should be soluble in neat alcohol. I have tried rubbing alcohol but I found that the slight improvement in colour in no way compensated for the unpleasant fumes of the dye bath. I had read that vodka might be a useful alternative, so I decided to try that.The vodka was then used as part of the dye bath, with water added. This might seem like a rather unsuitable use of vodka but it was the best alternative I could find.  In fact, I wouldn’t waste good vodka again, as the difference in colour, compared with the results without vodka, was negligible.

Alkanet root (Photo by Zuzana Krskova)

Fabrics from top: cotton, linen, silk Yarns from top: no modifier, +acid, +alkali, +copper, +iron

Pomegranate peel (Photo by Zuzana Krskova)

Details as above for alkanet

Cutch (Photo by Zuzana Krskova)

Details as above for alkanet

Alder cones and twigs dyed by Lizzie Kimbley  (Photo by Zuzana Krskova)

Details as above for alkanet

Some results laid out on the table  (Photo by Lizzie Kimbley)

Resist dyeing techniques

One of the sessions on the one-year course at Ditchling Museum was devoted to resist dyeing techniques, specifically to cassava paste resist, used traditionally in Nigeria, and Dhabu or mud resist, used in India. For the cassava paste resist the students either applied the paste to the fabric with a brush or used zinc or tin stencils from Nigeria, which I have as part of my textile collection. The mud resist paste was applied to the fabric either with a brush or using carved wooden blocks.

The mud resist paste was bought from Saith Ffynnon Wildlife Plants (link on home page) and came supplied as a dry mixture for combining with water.

The following notes are from the information sheets I prepared for the students.

Resist Pastes

 Resist Paste Clay from India (Dhabu) – use according to instructions supplied with paste. Pastes from rice flour & cassava flour can also be used. (Cassava flour paste is used in Nigerian indigo dyeing.)

Cassava flour resist paste   

 This is traditionally used as a resist in Nigerian Adire  indigo dyeing. The Adire is either produced by free-hand painting of cassava paste, Lafun, onto the cloth or by stencilling the starch on fabric. The stencils are made from corrugated zinc or a perforated tin sheet.

Reference: Cassava flour resist paste

The extract below is from the reference above. My interpretation follows.

“For every 1kg of flour of any type used in the study, 4 litres of water or more was used for the preparation. Some of the flour was prepared under hot condition and stirred on fire for a quarter of an hour as prescribed by Wolff (1985); that long stirring of paste prevents lumps. For the innovation, not all the paste was able to stand long stirring on fire as prescribed. For example, the cassava flour and starch prepared on fire for less than 10 minutes became too elastic and tough to manage. It could not be forced through the mesh for the screen printing application and for the stencil; it was too heavy thereby breaking the linoleum carpet, plastic and even the indigenous metal stencil. For cassava flour and starch, the paste was prepared with hot boiling water but not on fire. The cassava starch powder was melted in ½ a litre of cold water before 3½ litres of boiling water was poured and stirred to form the paste. After stirring, the paste was shared into ¼ kg in different bowls and mordant (caustic soda) which was considered most appropriate in this study was administered. Normally among the young producers today, 2 tablespoons full of caustic soda is the practice for 1 regular plastic measure of flour (Ike ijoba), but in this study for proper documentation and standardized measurement of the chemical for studio practise and general production, the study shared the paste into manageable quantity. In every ¼ kg, the two identified activators were administered. Alum was turned into crystal to carry same texture with caustic soda, one levelled table spoon full of each were administered in different bowl of the prepared paste, while in another, one and half and the final one, two levelled table spoons.”

My interpretation of this:

Use 4 litres of water to 1kg cassava flour. For 125gms flour use 500mls water. Carefully blend the flour first in 100mls cool water. Bring the remaining 400mls of the water to boiling point and then gradually stir it into the flour mixture, stirring constantly to create a smooth paste. If desired, add about a teaspoon of alum sulphate, first dissolved in some of the boiling water. (I’m not sure why this is traditionally added. In some cases copper sulphate (called “blue alum”) is also added, probably as a preservative. I usually omit both alum and copper sulphate.) If necessary, strain the mixture through a sieve to make sure it is free of lumps. Note: I have no idea why the caustic soda would be added; it is certainly not a mordant. When I attended a course with a Nigerian dyer she added alum and “blue alum” (copper sulphate) to the cassava paste solution but was unable to tell me why she did this.


Printing with marigold flowers and gum arabic

Printing with marigold flowers and guar gum

Printing with symplocos paste

Mud resist dyeing

Resist printing in Rajasthan

Cassava resist dyeing

Cassava resist dyeing

Ross Belton applying Dhabu mud resist

Students applying cassava paste resist through metal stencils from Nigeria

Close up of one of the metal stencils

Dhabu resist

Cassava paste resist

All photos by Helen Gibbs

Printing and painting with natural dye extracts

As part of the one-year natural dyeing course at Ditchling Museum I taught an experimental session on using natural dye extracts for fabric printing and painting. This is not an area in which I claim to have much expertise, so I was interested to see what my students would be able to achieve.

The following notes are from the information sheets I prepared and gave the students. I also recommended them to look at Helen Melvin’s useful booklet: Colours of the Rainbow: Painting Fibres and Fabrics with Extract Dyes    This is available from Helen at Fiery Felts, to which there is a link on my home page.

We used only gum tragacanth as a thickener and experimented with different degrees of fluidity, depending on which process we were using. For example, the consistency of the paste required for block printing differs from the consistency required for screen printing. We also found that block printing worked best if the thickened extracts were applied to the block with a paintbrush, rather than pressing the block into the dye solution. Application with a brush enabled students to cover only the areas for printing, whereas we found that dipping the blocks in the dye solution tended to blur the images because the dye spread into the areas between the carved design.


Making up dye extract solutions (NB See also section on Thickeners below) 

Use half a teaspoon extract to 50mls very hot water but use less (¼ tsp) for cochineal & logwood & more (1tsp) for cutch & madder. NB With cutch, madder, myrobalan, quebracho & lac/madder mix to a paste with cold water before adding hot water. If you intend to thicken the extract solution, use 15mls water and 35mls gum tragacanth thickener solution, instead of 50mls water.

For colour changes 

Dissolve 1tsp ferrous sulphate in 100mls very hot water and strain through a coffee filter paper. Then paint this over the dye. To change madder red to orange, logwood purple to grey & cochineal pink to red, dissolve 1tsp of cream of tartar in 50mls hot water & paint this over the dye.


Fabric should be mordanted first or the mordant solution can be brushed onto the fabric. Mix 10gms alum sulphate (animal fibres) or ¼tsp aluminium acetate (veg. fibres) with 100mls hot water. Brush the solution onto the fabric, and steam it for 30 minutes. Note: for deeper colours the mordant solution can be brushed on several times before steaming the fabric. Alternatively, the dissolved aluminium acetate mordant can be mixed with the dye solution, using 1/8 tsp for every 50mls of boiling water. Dissolve the aluminium acetate first in the boiling water then add the extract to it & dissolve completely before applying the mixture to the fabric. If using alum sulphate, dissolve it using 5gms per 50mls of boiling water.


With all the thickeners careful mixing is crucial. With gum arabic use water at room temperature and sprinkle the powder on the surface of the water, whisking as you do so. Continue whisking until the solution is glossy & not lumpy.

Gum tragacanth – use to thicken dye extracts. This is the most expensive of the thickeners & also the best. Use as follows: Mix 1 tablespoon of gum tragacanth with 250mls of boiling water and liquidise or hand whisk until glossy. The mixed gum tragacanth thickener can be kept for 6 months in the fridge. To thicken dye, add 15mls water to the dye extract & 35mls gum tragacanth solution. To thicken left-over dye solutions, add 1 tablespoon thickener to 2 tablespoons dye. Stir vigorously with a glass rod or whisk until smooth.

Gum Arabic – use with dye extracts & mordants. Use 10 to 12gms per 100mls dye or mordant solution. Mix very carefully & thoroughly. Gum arabic is less expensive than gum tragacanth but does not give such good results. However, it is fine for tests & experiments.                                                                                                                         

For further info:

Mordant printing 

Put 25mls gum tragacanth solution into a pot & add ¼tsp ferrous sulphate or aluminium sulphate. Mix very well & then print or stencil using this solution. Then brush on dye solution using a household paint brush. With iron mordant, black can be achieved if tannin-rich dyes are used, for example walnut, pomegranate & myrobalan.                                                                                                                                                     

Making a surface for printing or stencilling     

Use 2 or more layers of bubble wrap, depending on thickness, & fasten it down with masking tape. Put a layer of clingfilm on top then the fabric and fix down with masking tape. Then fix the stencil over the fabric, again with masking tape, & brush on thickened dye.

Printing or stamping     

Place the thickened dye mixture into a shallow dish. Press the stamp or printing block into the dye solution & press lightly onto kitchen paper to remove surplus dye. Then press firmly onto the mordanted fabric. Alternatively, print on the thickened mordant solution and then print or paint on the dye.

Setting the painted, printed or stencilled natural dye extracts   

Allow the fabric to dry then wrap the fabric in clingfilm making sure no two painted surfaces come into contact with one another. Start by laying the clingfilm under the fabric before you start to paint then cover the first few inches of painted surface with another layer of clingfilm & begin to fold the fabric on top of itself. Then steam the fabric for 30 to 45 minutes and allow the fibres to air cure for a further week before washing. Alternatively, air cure the fabric for one month before washing.

This is one of the prints made by Helen Gibbs

Screen print by Helen Gibbs

Painted and stitched piece by Susan D’souza

Block prints by Susan D’souza

One-year natural Dyeing Course at Ditchling Museum (4)

In this session we started sampling adjective dyes, which are dyes that require the use of a mordant, usually alum.

The dyes we used included two of the dyes introduced into Europe at the beginning of the 16th century from South & Central America. They are: Logwood (Haematoxylon campechianum) & Fustic (Chlorophora tinctoria). I had originally planned to use Brazilwood (Caesalpinia echinata), another dye introduced into Europe from South America at the beginning of the 16th century, but this is currently unavailable because it is becoming endangered.

So the third dye we used was Sappanwood (Caesalpinia sappan), from India, Malaysia and South-East Asia. Sappanwood is the form of brazilwood known from the 13th century as a red dye in the East, where it was called “brasil” or “bresil”, meaning “glowing like fire”. It was also known in Europe from the late Middle Ages and was imported by the land route. An indication of its importance can be seen by the fact that it gave its name to the country Brazil. When explorers arrived in that part of South America, similar trees were found growing there abundantly, so the country was named terra de brasil after the tree. It gives colours very similar to those from Caesalpinia echinata, but with a slightly pinker tone.

The mordants we used were 10% aluminium sulphate for the animal fibres and 5% aluminium acetate for the vegetable fibres. We also experimented with symplocos powder as a natural source of aluminium from symplocos leaves and we used this with logwood and sappanwood on both animal and vegetable fibres. (See my earlier post “Symplocos leaves as a source of aluminium mordant”)

Note: for improved colour fastness from logwood on animal fibres, it is advisable to use 24% alum. 

As with the substantive dyes we tested, we applied colour modifiers to the fibres after dyeing.

LOGWOOD 50% (alum mordant) Samples in the following order: Top – linen, silk, cotton Below – No modifier, acidic modifier, alkaline modifier, copper modifier, iron modifier

LOGWOOD 50% (symplocos mordant)  Samples as above for logwood with alum 

I think 50% logwood was too high a percentage for the colour variations from the modifiers to be clearly visible. We should have used no more than 30% to show the effects of the colour modifiers.

SAPPANWOOD 100% (alum mordant) Samples: top – cotton, linen, silk Below –  as for logwood above

SAPPANWOOD 100% (symplocos mordant)  Samples: top – cotton, linen, silk  Below –  as for logwood above

FUSTIC 100% (alum mordant) Samples: top – cotton, silk, linen  Below – as for logwood above 

I was a little disappointed with the fustic results. I had expected much stronger colours and I think we probably didn’t simmer the dyestuff long enough to extract all the colour potential. 

It is always difficult in workshops, when one so frequently seems to be working against the clock, to allow enough time for all the stages and processes involved in natural dyeing. When working at home, it is important to remember that each process needs time and should not be rushed, if one wants the best results. The “look” of the dye bath will often indicate whether more time is needed for colour extraction or colour application and experience is also an important factor.                                                    

At this session we also made our first indigo vat, using washing soda or wood ash water as the source of alkali and sodium hydrosulphite as the reducing agent. We also made a vat using a stock solution.

As an experiment I made a stock solution using wood ash water instead of caustic soda. (See my earlier post “Making and using an indigo stock solution”)

I mixed the indigo powder into a paste with hot water as usual, then added it to about half a litre of wood ash water, which I had first heated to about 50C. I then added sodium hydrosulphite and left the stock solution to reduce. After about an hour, it became a dull yellow-green colour and when I used it to make a vat it worked quite well.

The stock solution made using wood ash water as the source of alkali

INDIGO vat made using one tablespoon of stock solution Upper samples soaked for 2 minutes and the lower samples soaked for 5 minutes Order of fabrics: cotton, silk, linen

All photos above by Ross Belton

On the “Show & Tell” table this session was a display of the little books made by Helen Gibbs and dyed mainly with various tree barks. They are really beautiful and just wonderful to touch and open.

Photos by Helen Gibbs


More from the one-year natural dyeing course at Ditchling Museum (3)

At this session we concentrated on dyeing with alkanet root (Alkanna tinctoria), cutch (Acacia catechu) and rhubarb root (Rheum spp.) All these dyes are substantive, so no mordant is necessary. However, we added an alum-mordanted wool sample to the alkanet dye bath, as this should give a lavender shade. As usual, we tested the dyes on wool, silk, cotton and linen fibres and applied modifiers after dyeing. As modifiers we used clear vinegar (acidic), soda ash (alkaline), copper water and iron water.

To simplify the process, we tied the alkanet root and the rhubarb root into muslin bags before adding the water to the dye pots. This means the dye bag can be removed from the dye pot once the colour has been extracted, so there is no need to strain off the dye liquid. The dyestuff in the bag can usually be simmered again for a further dye bath.

With the exception of cutch, the dye baths were prepared by simmering the dyestuff for about 40 minutes to extract the dye colour. Cutch is usually supplied as an extract in powder form, so it needs only to be carefully mixed with warm water and then stirred into the dye bath. It is important to make sure the cutch has dissolved completely, otherwise any loose particles will cause stains and spots on the fibres.


Alkanet root before being chopped (Photo by Jennifer Nightingale)


Light and dark cutch blocks before being made into powder (Photos by Jennifer Nightingale)

Cutch dye solution

Alkanet root dye solution

Rhubarb root dye solution


Left: see below Centre: from top – linen, cotton, silk Right: paper samples

From left: no modifier, + acid, + alkali, + copper, + iron (photos by Ross Belton)

Alkanet root produces a less than pleasant aroma when simmered and without a mordant usually gives colours in the grey/green/brown range. The purple dye is best extracted by soaking the root in rubbing alcohol or vodka for several days or even weeks before simmering it for dyeing. However, the dyeing process produces unpleasant fumes and great care must be taken to keep the solution away from naked flames, as it could easily catch fire. And it cannot always be guaranteed to produce purples. (See my earlier post on Alkanet Root for more details.) Unfortunately, using an alum mordant did not guarantee purple either this time, so once again my experiments with alkanet had limited success.

In Japan, the roots of the purple gromwell plant, Lithospermum erythrorhizon, which look very like the roots of Alkanna tinctoria, are used and tend to more reliably produce lavender and purple shades.


Left: as above for cutch Centre: from top – linen, cotton, silk Right: paper sample

From left: as above for cutch (Photos by Ross Belton)

Rhubarb root is always interesting to use, as it reacts so positively to the modifiers and a wide range of shades can be achieved. And as an added bonus it doesn’t smell unpleasant either.


Left: paper samples Centre: from top – linen, cotton, silk Right: as for cutch

From left: as above for cutch (Photos by Ross Belton)

Part of each session is devoted to assembling the dried samples from the previous month onto sample cards and it is always a pleasure to see the results from each session.

The tasks of mordanting and preparing samples is also ongoing and at this session we treated animal fibres with a rhubarb leaf base and also mordanted more fibres with tannin. We will be using these samples at a later date.


One-year natural dyeing course at Ditchling Museum: 2nd session

At the second session of this course we continued washing animal and vegetable fibres and mordanting them with aluminium and tannin. 

We also dyed wool, silk, cotton and linen samples using walnut leaves and walnut hulls (Juglans spp.) After dyeing, the samples were then treated with an acidic modifier (clear vinegar), an alkaline modifier (soda ash), a copper modifier and an iron modifier.

Dyes from walnut leaves and hulls do not require a mordant, so the samples had only been thoroughly washed before dyeing.


1. Samples removed from the walnut leaves dye bath                                                                                                            


2. Samples removed from the walnut hulls dye bath                                                                                                                    


3. Samples waiting to be modified, with the modifier solutions in bottles                                                                            

I usually fill bottles with the modifier solutions in advance, so they are ready to use when needed. It is easy to adjust the quantity added, according to the depth of colour change desired. Start by adding a little modifier solution and then add more if the colour change is too insignificant. Keep the unmodified sample to hand, in order to check that each modifier result gives a slightly different tone and all are a little different from the unmodified samples. With some dyes the differences in shade can be quite dramatic, while with others the differences may be difficult to discern.


4. Results from walnut leaves  

Above: cotton, silk, linen Below from left to right: no modifier, + acid, + alkali, + copper, + iron ( each with wool & silk on the left & cotton & linen on the right) 

(Photos 1, 2, 3, 4 by Ross Belton)

Some notes on dyeing with walnut hulls:

Fresh green walnut hulls, if used before they turn brown, can give lovely rich deep browns but dried walnut hulls usually give paler browns. As we only had dried walnut hulls, we conducted a further experiment with them to attempt to achieve a deeper brown by making the pH of the dye bath more acidic. So after simmering the walnut hulls to extract the colour, we added clear vinegar to about pH4 and then dyed some fibres in the usual way. This produced a deeper brown. 


5. Results from walnut hulls 

(Photo 5 by Zuzana Krskova)

Above: silk, linen, cotton Below as for walnut leaves with extra samples far right showing the results from the dye bath to which vinegar to pH4 had been added. Note that the colour on the wool and silk samples is considerably deeper but the cotton sample shows little difference.

Note: Adding some oak gall solution to the walnut hull dye bath also gives a deeper brown and this is an attractive grey/brown. The oak gall solution can be added to the walnut hull dye bath either in addition to the vinegar or instead of the vinegar. (As a rough guide, add about 250mls oak gall solution per 2 litres of dye solution.) I often use an oak gall exhaust solution in this way.

Although walnut leaves and hulls can be used without a mordant, one of the students added an alum-mordanted wool skein to the walnut leaf dye bath and was delighted to find it dyed a lovely rich yellow colour. Mordanted samples can be added to any substantive dye baths and will often give slightly different colours than those on unmordanted fibres. However, using mordanted fibres does not necessarily mean that the dyed colours will be more light-fast. Indeed, walnut leaves give faster colours without a mordant and using an alum mordant reduces the light fastness. (See Gill Dalby’s book Natural DyesFast or Fugitive for more details.)

In general, dyes from walnuts are more suitable for animal fibres, unless copper or iron modifiers are used. 

At this session we also had a “Show and Tell” table. The photos below show some of the items on the table, all made by the students using the natural dyes we have sampled so far. 


(Photo by Zuzana Krskova)


(Photo by Zuzana Krskova)


One Year Natural Dyeing Course at Ditchling Museum – First session

The first session of this one-year course was on March 18th and I was delighted when I met the 12 students we had selected. The range of skills they represent include weaving, bookbinding, papermaking, basketmaking, costume designing, feltmaking and several other art and craft practices. Their interest and enthusiasm, together with their searching, intelligent questions make the group both a joy and a challenge to work with.

At this first session, after the students had talked a little about themselves and their creative practices, I gave a general introduction to the history of natural dyeing and the most significant dyestuffs and outlined the contents of the course and some of the techniques we would be covering. I also explained the difference between dyes and stains and emphasised the importance of selecting dyes with good levels of fastness, especially if producing articles for sale. We then set up some mordant baths using aluminium potassium sulphate for the protein (animal) fibres and aluminium acetate for the cellulose (vegetable) fibres. We also used tannin as a mordant and at the May session we will embark on mordanting using aluminium from symplocos leaves (see my earlier post on symplocos) and preparing wool and silk fibres with rhubarb leaf base.

The first dye we used was buckthorn bark. This might have been alder buckthorn (Frangula alnus) or common buckthorn (Rhamnus cathartica) but, as the label merely stated buckthorn bark, I couldn’t be sure which it was. Both give similar, if not identical, colours, so it didn’t really matter. (Note to suppliers: It would be very helpful to have the botanical names on the packets for accurate identification.)

We used wool, silk, cotton and linen yarns and pieces of silk, cotton and linen fabric and, as buckthorn bark is a substantive dye, we didn’t use a mordant. After dyeing, the samples were modified using 4 modifiers: an acidic modifier (clear vinegar), an alkaline modifier (soda ash), and copper and iron modifiers. Two sets of samples remained unmodified, one for purposes of comparison and the other to be over-dyed with indigo at a later date. This method of sampling will be used for all the dyes we test, with a few variations for specific dyes.

The students also wound more skeins and cut more pieces of fabric for later sessions.

The photos below show some of processes and the results.

                                                                                                                                      Wool and silk samples in the buckthorn bark dye pot

                                                                                                                                     Modifying the samples

The above 2 photos courtesy of Susan D’souza


                                                                                                                                                      Buckthorn bark samples

                                                                                                                                                      Buckthorn bark samples from left to right: no modifier, copper modifier, iron modifier, acidic modifier, alkaline modifier

                                                                                                                                                        Close-up of some buckthorn bark samples

                                                                                                                                                        Some more buckthorn bark samples

                                                                                                                                    Buckthorn bark yarns from left to right above: no mod, copper, iron, acid, alkali; fabrics below: cotton, linen, silk

The above 5 photos courtesy of Ross Belton

Note: I am extremely limited in what I am able to manage physically and this course would not be possible without the support of my wonderful assistant, Deborah Barker. I am so grateful to her for all her help in making everything run smoothly.


Soya milk – meadowsweet samples

At last I have found the meadowsweet samples missing from the earlier post on soya milk, so here they are:

Top from the left: cotton yarn, cotton fabric, linen fabric – all treated with soya milk & dyed in meadowsweet

Below from left: wool treated with soya milk & dyed in meadowsweet, wool mordanted with alum sulphate & dyed in meadowsweet

For more details see the post:

Soya milk / soymilk solution – what is it used for? Is it a mordant?

Soya milk / soymilk solution – what is it used for? Is it a mordant?

I am rather puzzled by the many references I have seen recently to soya milk/soymilk “mordant”as I would not describe soya milk as a mordant, rather as an assistant in certain dyeing and fabric patterning processes. In my understanding, soya milk has the same purpose in Japan as buffalo milk has on the Indian Sub-Continent – in both cases the milk solution is used as a binder or sizing agent, applied to fabric before mordanting or dyeing, in order to increase absorption and to prevent wicking and improve the sharpness of the outlines when painting or printing mordants, pigments and dyes on fabrics. Unlike a true mordant, soya milk solution does not form a chemical bond. I have never known soya milk solution to be traditionally applied to yarns rather than to fabrics and as far as I know it is not commonly used on woollen fibres. However, as my experience of using soya milk solution is not extensive, I decided to conduct some tests.

I prepared the soya milk solution as follows, using information from John Marshall, (, who is an expert in this field. I soaked one cup of soya beans overnight in three times their volume of water and then, when they had swollen, I strained the water off and rinsed the beans. I then added water to the beans (again three times their volume) and processed the mixture in a blender until the beans were well ground. I then poured the mixture through a piece of fine cloth spread over the top of a bowl and strained off all the liquid. I repeated this process three times with the same beans, each time adding the blended liquid to the previous solution. The final combined solution should be about the same consistency as cow’s milk and must be used fresh; as soon as it starts to become sour it should be discarded.

I then poured the soya solution into a bucket and added the washed and wetted materials. If necessary, more water should be added to allow the materials free movement in the liquid. I left the materials to soak for about 12 hours, moving them around from time to time, then removed them, squeezed them well and left them to dry. I repeated this process twice more but leaving the materials in the soya milk for only 5 minutes each time. I then left the materials to dry and cure for 2 weeks before using them. I then tested the materials treated with soya milk in dyebaths of madder and meadowsweet.

The madder samples are below.


MADDER ROOT Top from left: linen fabric, cotton yarn, cotton fabric, silk fabric, wool yarn (all soya milk pre-treatment & no mordant) Below from left: cotton fabric (no soya milk treatment & no mordant), wool yarn (alum mordant) I think these samples clearly show that, while the soya milk treatment improved the take-up of the dye, it did not act as a mordant in the way that alum does. That is to say, it did not give the red colour associated with madder on an alum mordant and produced the sort of colour one would expect from madder applied without a mordant. While soya milk is certainly useful in some circumstances as a pre-treatment for fabrics, I think it is misleading to imply it can be used instead of an actual mordant and this may lead to disappointment.

Note: the meadowsweet samples, which I have mislaid, showed even more clearly that the soya milk did not really act as a mordant. Meadowsweet gave only a very pale colour on both the soya milk treated materials and the untreated materials but it gave a bright yellow on the alum-mordanted materials.

PS Below are the meadowsweet samples – found at last!

Top from the left: cotton yarn, cotton fabric, linen fabric – all treated with soya milk & dyed in meadowsweet

Below from left: wool treated with soya milk & dyed in meadowsweet, wool mordanted with alum sulphate & dyed in meadowsweet