Resist dyeing techniques

March 25th, 2019

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.

USEFUL WEBSITES

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

February 21st, 2019

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.

NOTES ON PRINTING ETC WITH NATURAL DYE EXTRACTS

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.

Mordants     

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.

Thickeners 

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:  http://plantmordant.org/symplocos/printing-with-symplocos-paste

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

More news from the Ditchling Museum course

December 18th, 2018

I’m afraid I have got rather behind with posts about the one-year natural dyeing course, so here is an update of what we have been doing. Photos will follow as soon as I have some from the students. (I rarely get time to take photos myself during the sessions, so I rely on my students for images.)

We have covered a range of topics since my last post. They include:

Contact Printing using plant materials 

      

Some of the students’ contact printed scarves

Tests using different percentages of alum mordant         

Dyeing black using tannin and iron and dyeing black using weld, madder and indigo

Overdyeing in indigo     

Setting up fastness tests using samples dyed with avocado stones         

Dyeing yellow and pink with safflower   

Dyeing with sticklac (Recipe from Colours from Nature p61)

Sticklac before extracting the colour

Adding clear vinegar to pH4 to assist colour extraction 

Results from the sticklac dye bath Fabrics from top: silk, cotton, linen Yarns from left: no modifier, + acid, + alkali, + copper, + iron

Using the alkaline extraction method with madder, rhubarb root and buckthorn bark (Recipe from Colours from Nature p36

Testing the pH for the alkaline colour extraction method. 

For an excellent overview of the course, with photos, I would recommend the blog diary kept by Helen Gibbs: 
https://blogs.brighton.ac.uk/naturalcolour/2018/12/15/iron-black-redipped/

If you click on the above link you can then navigate forwards and backwards to see all the posts from the beginning of the course.

All photos by Helen Gibbs

 

Re-issue of the UK edition of “Wild Colour” in hardback

November 10th, 2018

I’m delighted to report that the UK edition of my book Wild Colour will be available in hardback from December 6th 2018. It has a new cover but the contents remain the same. Below is an extract from the publisher’s press release.

WILD COLOUR

HOW TO MAKE & USE NATURAL DYES

Jenny Dean

Mitchell Beazley | £16.99 | 6 December 2018

Wild Colour is a celebration of the wealth of natural dyes that can be obtained from plants, from the common marigold to rhubarb.

This practical and inspiring guide to creating and using natural dyes from plants offers information on current environmentally friendly dyeing techniques and more than 65 species of plants and natural dyestuffs.

This comprehensive book outlines how to:

  • Select fibres and plant parts
  • Choose the right methods for mordanting and dyeing
  • Obtain a range of gorgeous colours from every plant

Wild Colour is the all-in-one resource for fibre enthusiasts, including knitters, sewers and weavers, gardeners who are interested in new uses for traditional dye plants and eco-conscious DIYers who want authoritative information about the natural dyeing process and the plants that are essential for it.

About the Author

Jenny Dean has been working with natural dyes for four decades. She lectures on natural dyeing and has written widely on the subject. Her books include Colours from Nature and A Heritage of Colour.

For more information please contact Ellen Bashford on:

ellen.bashford@octopusbooks.co.uk or 020 3122 6701 136

 

 

Ditchling Museum Natural Dyeing Course (5)

October 31st, 2018

I’m afraid this is rather late as I’ve been seriously ill in hospital again and had to postpone the August session at Ditchling Museum.

This post should catch up on what we did at the last session before my illness, when we used madder, cochineal and weld. We followed the usual methods and prepared fibres with aluminium sulphate for wool and silk and aluminium acetate for cotton and linen. With madder and cochineal, we also used aluminium from Symplocos leaves as a mordant for all fibres. (See earlier posts for Symplocos mordanting details.)

WELD 100%

The colour from weld was extracted in the usual way, simmering it for about 30 minutes. When the dye liquid had been strained off and the fibres added, the temperature of the dye bath was kept just below simmering point to achieve clearer colours. We used both dried weld and fresh weld for comparison purposes.

 Photo by Zuzana Krskova

Weld dye bath

 Photo by Ross Belton

Dried weld results – From left above: linen, cotton, silk From left below: cotton & linen wool & silk, no mod, + acid, + alkali, + copper, + iron (All alum mordant)

 Photo by Ross Belton

Fresh weld results – From left: cotton & linen, wool & silk, no mod, + acid, + alkali, + copper, + iron (All alum mordant)

 Photo by Zuzana Krskova

Close up of some weld results – From left: cotton & linen, wool & silk, no mod, + acid, + alkali, + copper, + iron (All alum mordant)

COCHINEAL 30%

The colour was extracted from the cochineal using the multiple extraction method described on p59 of Colours from Nature. For this method the same whole (or ground) cochineal is simmered three times and the extracted colour is strained and added to the dye bath after each extraction. The solutions from the three extractions form the dye bath. It is a good idea to strain the final solution through a coffee filter paper to remove any loose particles which might cause blotches on the fibres but we didn’t do this as we didn’t have the necessary equipment. The fibres were added to the dye bath and simmered for 30 to 45 minutes.

 Photo by Zuzana Krskova

Cochineal dye bath

(More cochineal photos to follow)

MADDER ROOT 100%

The chopped madder root was used according to the following recipe: first wash the madder in a sieve under running water for a few seconds. Then pour boiling water over it, leave it to soak for about 30 seconds and then strain off this liquid and put it aside for a second dye bath later. Repeat this process and add the strained-off liquid to the first liquid. Then put the same madder root into a pot and simmer it for about 30 minutes to extract the dye colour. Strain off this liquid which becomes the first dye bath. Allow it to cool a little, then add the fibres and leave them to steep in the dye bath for about 45 minutes. If a deeper colour is required, the dye bath can be heated for 30 to 45 minutes but keep the temperature below simmering point. Then allow the fibres to cool in the dye bath.

The solutions from the first two soakings give a second dye bath, which can be used either cool or heated as above. However, I’m afraid we produced no samples from this second dye bath as it was discarded in error.

This method of dyeing with madder differs from some other methods but usually gives clear corals and reds, depending on the strength of the dye bath and the length of time the fibres are in it. For really deep colours, it is often necessary to use 200% madder to dry weight of fibres, especially if dyeing vegetable fibres.

 Photo by Zuzana Krskova

Madder dye bath

 Photo by Ross Belton

Madder root – Top from left: linen, silk, cotton Below from left: From left below: wool & silk, cotton & linen no mod, + acid, + alkali, + copper, + iron (All alum mordant)

 Photo by Ross Belton

Madder root – Top from left: cotton, linen, silk  Below from left: wool & silk, cotton & linen no mod, + acid, + alkali, + copper, + iron (All Symplocos mordant)

 Photo by Ross Belton

Tannin is not necessary when using aluminium acetate and this was an extra experiment to see if using tannin before applying aluminium acetate improved the colours.  Unsurprisingly, it didn’t. Top: cotton, below: linen 

Ditchling Museum Natural Dyeing Course (6) – Woad, Japanese Indigo & Saxon Blue Day

October 15th, 2018

Unfortunately I’ve been seriously ill in hospital again, so the August session at Ditchling Museum was cancelled and we used the September session to harvest and use the woad and Japanese indigo (Persicaria tinctoria) before it was too late in the season. At this session we also used Saxon Blue.

After we had used the woad and Japanese indigo leaves for blue, we simmered the same leaves to make a dye bath for tans.

WOAD

One of the students brought some woad leaves, which were chopped and then we poured boiling water over them and left them to steep for about an hour. Then the liquid was then strained off  and the leaves squeezed well to extract all the dye potential.When the liquid had cooled to 50C, soda ash was added to turn the liquid from brown to green and the liquid was whisked until the froth became blue and then whisked further until it started to turn white again. We allowed the froth to subside and then added a reducing agent, sodium hydrosulphite, to remove the oxygen. When the liquid below the surface had become greeny yellow, the vat was ready to use.

NOTE: As woad is said to prefer soft water, it is a good idea to use rain water for woad vats. However, I rarely remember this and have always found the ordinary water from my tap produces a perfectly good woad vat. I have also read that the dye solution should be cooled quickly to 50C, so some people put the container of woad solution into a second container of cold water and sometimes add ice cubes to speed up the cooling process. This is not something I tend to do and my woad vats are always fine but they might be even better if I remembered to cool them down quickly.

Straining off the woad solution after the leaves had been steeped in the boiling or very hot water

Blue froth forming as the liquid is whisked

Results from the woad vat Left to right: cotton, wool, silk noil, silk fabric, cotton fabric, linen fabric with 2 wool samples

Results from the woad leaves simmered for a tan dye bath From left: NM wool, NM silk, NM cotton, NM linen, alum wool, alum silk, alum cotton, alum linen (NM = no mordant) Note: All the cotton & linen samples are actually pink, not blue, in tone

JAPANESE INDIGO

My Japanese indigo had already started to form seed, so the blue dye potential was reduced and the results were rather disappointing. Luckily, one of the students brought some of her own Japanese indigo leaves and we tried two methods – the usual vat method and the water and vinegar method.

In the vat method the Japanese indigo leaves are torn or cut up into small pieces, covered with cool to warm water and brought to simmering point over a period of about 1 to 2 hours. (Note that this differs from the woad method in that boiling water is not poured over the leaves, but they are first covered with cool to warm water and then heated gradually.) The leaves are then left to steep in the hot water for about an hour. Then the liquid is strained off  and the leaves are squeezed well to extract all the dye potential. When the liquid has cooled to 50C, the dye vat is then made in the same way as described above for woad. 

Cutting up the Japanese indigo leaves

The cut leaves

The water and vinegar method requires at least 200% fresh leaves and this method gives blues which may be less stable or permanent that the blues from the more traditional methods of dyeing with woad/indigo. However, this method requires only water and clear 5% vinegar. The vinegar should be added at the rate of about 15mls clear vinegar per litre of water. Harvest the leaves and process them immediately. Chop or cut up the leaves as finely as possible, preferably not using a wooden chopping board, as this may absorb too much of the precious dye solution, or process them with a little water in a liquidiser. Put the chopped leaves into a container and add enough water to cover them. Then add the vinegar and knead the leaves very well for at least 5 minutes until the liquid is bright green. Strain off the liquid and set it aside. Knead the leaves again in water and vinegar as before, strain off this liquid and add it to the liquid reserved from the first kneading process. Immerse the fibres immediately in the liquid and leave them to soak for about one hour. Then rinse them in clear water and air them. Finally, add a small amount of fibres to the liquid and leave them overnight to exhaust any remaining dye potential, then rinse and air them.

NOTE: I have read that some dyers use iced water without the addition of vinegar but I have not tried this.

This shows the fibres being immersed in the water/vinegar Japanese indigo solution (Photo by Ross Belton)

SAXON BLUE

Saxon blue or sulphonated indigo is an indigo extract made by dissolving indigo powder in sulphuric acid. The process was discovered around 1740. It is called Saxon Blue because the blues it produced resembled the blues of ceramic wares based on cobalt and Saxony was the centre of that industry.

Saxon Blue is used mainly for dyeing wool and silk and produces blues with a turquoise tone. Blues from Saxon Blue may be less fast to light and washing than indigo blues made by the vat method and deep blues from Saxon Blue have higher levels of fastness than paler shades. There is some disagreement about whether an alum mordant is needed for Saxon Blue. I tend to prefer to use an alum mordant, as this seems to produce deeper, clearer blues.

Saxon Blue is simple to use. Prepare the hot water for the dye bath and then just stir in some Saxon Blue liquid. How much one needs to use depends on the depth of blue required and the amount of fibre being dyed. I usually start with one or two teaspoons and then add more if necessary. Then add the fibres, bring the dye liquid up to simmering point and simmer gently for 30 to 45 minutes. Then leave to cool before rinsing.

The Saxon Blue we used was bought from Fiery Felts (see link under Useful Websites) and made by Helen Melvin. This gives excellent blues and a little goes a long way.

This shows some results on silk: top – Saxon Blue, below left – Japanese indigo vat method, below right – Japanese indigo water & vinegar method (Photo by Ross Belton)

Ditchling Museum Anniversary Open day

October 4th, 2018

As I’ve recently been seriously ill in hospital again, I had to postpone the last Ditchling Museum natural dyeing course session but I was sufficiently recovered to be part of the museum’s open day on September 22nd. This was to celebrate the 5th anniversary of the opening of the new museum buildings and the museum offered free entry all day, with a variety of activities, a barbecue and live music.

Unfortunately the weather was rather cold and rainy in the afternoon but the activities offered by some of my dyeing course students proved very popular, even those that took place outside. Among the activities on offer were handspinning, weaving, stitching, paper making, mark making with botanical inks and handmade brushes and the opportunity to use an indigo vat.

We set up the indigo vat using natural indigo, soda ash and sodium hydrosulphite, with a stock solution on hand to top up the vat when necessary. We also offered a chance to learn some shibori techniques and the results brought smiles of delight to all those who participated.

The museum’s dye garden was not as spectacular as it had been earlier in the Summer but it was still flourishing and we had a display of solar dye pots using plants from the dye garden.

Part of the dye garden earlier in the season with yellow cosmos, French marigolds, yarrow, St. John’s Wort and safflower, with madder in flower in the background

An interesting way to display solar dye pot results, all from dyes grown in the museum’s dye garden.  (Photo courtesy of Sue Craig)

  

Ross Belton with his botanical inks and handmade brushes and some of his indigo-dyed fabrics in the background

  

Some results of mark-making with Ross’s botanical inks

  

Sarah Matcham and weavers

Having a go at weaving under Sarah’s supervision

  

Jane Ponsford and paper makers

  

Some samples of hand-made paper

  

Lottie Whyman with a young stitcher

  

Jennifer Nightingale demonstrating handspinning

  

The indigo vat in use. Zuzana Krskova and Jackie Sweet help unwrap a shibori-dyed tote bag, as it comes out of the post-dyeing clear water dip. Below are some results from the indigo vat.

  

  

All photos by Jonny Dredge unless otherwise indicated

 

 

 

2nd Revised Edition of “Colours from Nature”

August 5th, 2018

I have recently revised and reprinted my book “Colours from Nature”.

It has 11 extra full colour pages with many more photos and it has a coiled (spiral) binding so it will lie flat for ease of use and an acetate outer cover to protect it from splashes.

Some of the text has been changed or expanded; for example: there is now a recipe for the indigo 123 vat, Symplocos leaf mordant is covered, there is a section on the alkaline extraction method and some of the recipes in the recipe section have been changed. (For more details about the book click on “My Books” on the home page.)

I feel this revised edition of “Colours from Nature” most closely represents my current dyeing practice and the dyes and methods I use personally. It is also the book I use as a text book with my students at Ditchling Museum.

At present this revised edition of  “Colours from Nature” can be purchased from D T Crafts in the UK (www.dtcrafts.co.uk) 

It can also be purchased in the USA from Botanical Colors (www.botanicalcolors.com)

 

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

July 26th, 2018

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)

June 23rd, 2018

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

CUTCH SAMPLES 

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.

ALKANET ROOT SAMPLES

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.

RHUBARB ROOT SAMPLES

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.