Archive for July, 2011

Anglo-Saxon dyes – Madder

Monday, July 18th, 2011

Madder (Rubia tinctorum) is one of the most ancient dyes and a particularly useful and reliable source of red. Other plants in the madder family (Rubiaceae) include the native plants lady’s bedstraw (Galium verum), wild madder (Rubia peregrina), hedge bedstraw (Galium mollugo), dyer’s woodruff (Asperula tinctoria) and woodruff (Galium odoratum).

Although madder (Rubia tinctorum) was available during the Roman period, it seems to have been replaced during the early Anglo-Saxon period by the native Rubiaceae (for example:lady’s bedstraw and wild madder). This suggests that the Romans imported madder as a dried dyestuff, rather than growing it in Britain, and that it disappeared with the departure of the Romans. There is evidence that madder began to be imported from France in the 7th century and by the later Anglo-Saxon period it had become a very common dye.

The analysis of dyes in textiles of the early Anglo-Saxon period seems to indicate that reds, like purples, were mainly used for narrow woven bands, headdresses, embroideries and accessories, such as bags, rather than for larger fabrics. Where dyes were used in larger fabrics (and dyes were detected in only one-third of the larger fabrics analysed) these were mainly dyes that give shades of yellow, blue and brown, plus green from blue and yellow dyes used in combination. It is also possible that, at least in the early Anglo-Saxon period, reds and purples were colours reserved for people of high status.

An alum mordant is necessary for true reds from madder (Rubia tinctorum) and reds achieved on a clubmoss mordant are very similar to those achieved on fibres mordanted with mineral alum. Without a mordant, madder gives colours in the orange to coral range and using a tannin mordant gives similar but slightly deeper colours. An alkaline modifier, such as wood-ash-water, makes the colours pinker in tone and an iron modifier makes the colours browner. The addition of chopped crab apples to the dyebath makes the colours brighter.

The first photo below shows a range of shades from madder (Rubia tinctorum)

In my experience it is not easy to obtain true rich reds from lady’s bedstraw, wild madder, dyer’s woodruff and woodruff. I grew all these for several years in my old garden but never managed to get the sort of red obtained from madder, also grown in my garden. The use of an alkaline (wood-ash-water) modifier moves these colours further towards red and an iron modifier makes the colours browner. I intend to continue experimenting with these dyes in the madder family – if, that is, I can grow enough roots to make the tests worth the effort. Lady’s bedstraw grows wild at the sides of many country roads in this area but it is against the law to uproot wild plants, so I shall have to rely on my home-grown plants and it will be a while before they are mature enough to harvest.

The second photo below shows colours from wild madder roots (upper left), wild madder dried tops (4 samples at lower left) and lady’s bedstraw (right)

The third photo shows colours from woodruff roots (Galium odoratum)



Anglo-Saxon mordants

Tuesday, July 12th, 2011

This is the next post about my Anglo-Saxon-style experiments.

Today’s natural dyers tend to use mainly aluminium mordants and sometimes iron and copper, which may also be used after dyeing as colour modifiers. Chrome, which was not introduced as a mordant until the 19th century, has been popular among some dyers but is avoided by many nowadays because of its toxicity. Similarly tin, which was first used as a mordant in the 17th century (mainly with cochineal to produce bright reds) is now less frequently used, partly because of environmental considerations and partly because it can make fibres brittle. Copper was used by early dyers in the Mediterranean world and also in India in the classical period AD300 – 700 but, of the metallic mordants mentioned above, only alum and iron seem to have been used by the Anglo-Saxons. It is also possible that pots made of metals, such as iron or bronze, may have been used as dyepots and this may have had an effect on the colours. However, the only evidence of dyestuffs staining pots in the early Anglo-Saxon period occurred in pots made of clay and dyeing may have frequently been carried out in clay pots, which would probably not have had a significant effect on the colours produced.

Many of the dyes used by Anglo-Saxon dyers will fix adequately without a mordant and I think it is likely that many fibres would have been dyed in this way. Some textile fragments from the period show evidence of an alum mordant and mineral alum from the Mediterranean was probably used during the later Anglo-Saxon period. However, there is some doubt as to whether this mineral alum would have been available earlier in the period, so alternative mordants may have been used, such as aluminium extracted from clubmosses. Plants rich in tannins, such as oak galls and blackberry leaves and shoots, may also have been used as mordants.

In my experiments I tested most dyes in the following ways:

  • Without a mordant
  • With a 10% mineral alum mordant
  • With alum extracted from clubmoss
  • With a tannin mordant (from oak galls or bramble/blackberry leaves and twigs)
  • With an iron mordant / use of an iron pot

As clubmosses are rare in Britain, I would not advocate their use, except in very small quantities for experimental purposes. For my tests I used the following recipe for clubmoss as a mordant:

Use 200% clubmoss (Lycopodium spp), chop it up and put it into a pot filled with water, then heat to 40C. Hold at this temperature for 3 days. On the fourth day boil it up briefly and then strain off the liquid. Add the fibres to be mordanted, heat slowly to 40C and then allow to cool  Repeat this process daily for 3 days. Then remove the fibres and squeeze the excess liquid back into the solution, which can be re-used once. In order to be sure that aluminium had been extracted and then absorbed by the fibres, I used fibres mordanted with 10% mineral alum and unmordanted fibres as “controls” in the dyebath. The results were particularly clear with madder dye – the unmordanted fibres dyed to a coral shade but both the alum-mordanted and the clubmoss mordanted fibres dyed to an almost identical red shade.

In these tests I used 100% bramble/blackberry leaves and twigs as a tannin mordant. I simmered them for about one hour to extract the tannin, then strained off the liquid, added the fibres and simmered them for about 45 minutes, then left them in the liquid to cool overnight. (25% oak galls can be used instead of bramble leaves and twigs.)

I also experimented with the use of iron and wood-ash-water, which is alkaline, as colour modifiers after dyeing. It is also possible that stale urine may have been added to dyebaths and this would have increased alkalinity.

To make iron water, put some pieces of scrap iron or rusty nails in a large container with a well-fitting lid and fill it up with a solution of two parts water to one part clear vinegar. Leave the iron to steep in this solution for a week or two, until the solution is orange in colour. When you use the iron water, strain it through a fine-meshed sieve or a piece of muslin.

To make wood-ash water, put the ashes from a wood fire into a large glass or plastic container with a well-fitting lid. Fill up with water and leave the ashes to steep for a week or two, until the liquid is yellow in colour and feels slick or slimy to the touch. When you use the solution, pour or siphon it off without disturbing the ash sediment. Wood-ash water can be used as an alkaline modifier and as the source of alkali in woad vats. It can also be added to dyer’s broom and weld dyebaths to increase the depth of colour.

My experiments are intended to demonstrate some of the possible methods used by Anglo-Saxon dyers and to give an idea of the colour range they might have achieved. Although we don’t know exactly how early dyers worked, there is enough evidence to indicate that they would have been able to achieve a wide range of bright, rich colours from the relatively small number of dyes they used.

I will write about individual dyes in later posts.

Indigo workshop

Sunday, July 3rd, 2011

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

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

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

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

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

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