Archive for the ‘General Dye Information’ Category

Mediaeval Dyes

Monday, June 10th, 2013

 

Following on from my earlier posts about Anglo-Saxon dyes, I thought I’d write a little about the dyes used in mediaeval Europe, from around the 9th century to the beginning of the 16th century.

 

As archaeological evidence and the technical analysis of textile fragments indicate, during this period dyers had access to a wider range of dyes as trade developed and increased. Indigo from woad (Isatis tinctoria) remained the main source of blue and madder ((Rubia tinctorum) was the most common source of reds, with kermes (Kermes vermilio) and sappanwood (Caesalpinia sappan) also being used. Weld (Reseda luteola) and dyer’s broom (Genista tinctoria) continued to be used for yellows and other sources of yellow included heather (Calluna vulgaris), bog myrtle (Myrica gale), Persian berries (Rhamnus spp.), Venetian sumac (Cotinus coggygria) and sometimes also saffron (Crocus sativus).

The Imperial or Tyrian Purple dye from shellfish, famed in the ancient world, was still being used, albeit on a much smaller scale, and some species of lichens were also used in many parts of Europe to produce a vivid, if less permanent, purple colour. The tannin/iron complex remained the most common method of creating black, although the preferred, but more costly, method was to use red, blue and yellow dyes in sequence.

There were also apparently regional differences in the use of colour. By the 11th century Flanders was known for green, the Rhineland for black and Britain for red. Within England itself, some towns were licensed during the mediaeval period to produce certain colours – for example, York for red and purple, Lincoln for green, scarlet and grey, Coventry for blue and Beverley for blue and red.

 

3 dyed skeins p6 - Copy

 

From left: Reds and rust from madder (alum mordant), brown & tan from walnut hulls (no mordant), gold & yellow from weld (alum mordant), moss greens from weld + iron modifier and blues from woad (no mordant)

 

40 black overdye p.44 lower - Copy for blog

 

Black from madder + weld + woad (alum mordant)

 

221 lichen purple samples p137 centre - Copy for blog

 

Purples from the lichen Ochrolechia tartarea (no mordant)

 

Trade flourished in the Middle Ages and the most expensive of all dyestuffs was the insect dye, kermes (Kermes vermilio), from a shield-louse that lives on the kermes oak, Quercus coccifera, found in various parts of the Mediterranean. Sappanwood, from the heartwood of the tree Caesalpinia sappan, was imported into Europe in the later Middle Ages from India, Ceylon and Java and gave red colours. The wood and the dye were known locally as “bresil” or “brasil” and when at the end of the 15th century Portugese explorers found a related tree, Caesalpinia echinata, growing in the country now known as Brazil, they named the country “terra de brasil” after the tree and the red dye from Caesalpinia echinata was called brazilwood. Sappanwood was brought into Europe in surprisingly large quantities and 80% of the reds analysed on fabrics from around 1100 to 1450 prove to have been dyed with at least some sappanwood. It was added to madder dyebaths to enhance the colour and was also used for browns and for some compound colours. Sanderswood (Pterocarpus santalinus) from India and Ceylon was also introduced in the later Middle Ages and was used for reddish rusts and compound colours.

 

247 kermes p149 upper left - Copy for blog2

 

Kermes (Kermes vermilio)

 

248 kermes samples 1 p149 upper right - Copy for blog

 

Red from kermes (alum mordant)

 

Mediterranean alum became more widely available and was imported into Britain from Italy, Spain and Asia Minor. Italy dominated trade and Italian dyers had access to dyes that were not generally available in many other parts of Europe. The 14th century archives of  Francesco di Datini in Florence and Prato list lac (Kerria lacca), an insect dye from India and South-East Asia, and indigo (Indigofera tinctoria) from Baghdad among their items of trade.

 

During the Middle Ages dyeing flourished in Europe and it was the craft of the dyer that added most to the value of textile fabrics. Guilds of master dyers became established and a master dyer’s recipe book was closely guarded. The list of dyes and details of dyeing techniques found in dyers’ recipe books of the period indicate the increased complexity of some of the methods. The first known manual written for the professional dyer was the Plictho de larte de tentori, which was a collection of recipes for dyeing wool, silk, cotton and linen. It was compiled by Gioanventura Rosetti, Master of the Arsenal in Venice, and published in Venice in 1548. This manual is an important document in the history of dye chemistry and technology and clearly shows the stage of development that the dyer’s craft had reached by the middle of the 16th century.

Dyeing brown and grey wool fibres

Sunday, March 24th, 2013

 

In my new book I am focusing to some extent on native plants and fibres, so wool plays an important part – and not only white wool but also naturally-coloured wool. Recently I have been spinning naturally-coloured light brown and grey wool fleece and I love the effects when these skeins are dyed. The colours can be very subtle. Here are some examples:

 

dyes-on-grey1

 

From left to right: Madder, Indigo, Rhubarb Root

The first skein in each pair shows the dye colour on white wool and the second skein shows the dye colour on light grey wool.

 

All the skeins are unmordanted.

 

P1000464

 

The samples above are from horsetail (left) and tansy (right) and show from left to right: alum mordant on white wool, no mordant + alkaline modifier on brown wool , no mordant + alkaline modifier on grey wool

 

I find alkaline modifiers extremely useful, especially when used on fibres that have not been mordanted with alum. Even when the colour on the dyed fibres looks rather insipid initially, an alkaline modifier can often deepen and brighten it. The results of alkaline modifiers on naturally-pigmented wool are particularly pleasing, as I think the samples above show.

P.S to the post about chickweed

Saturday, February 16th, 2013

 

On Leena Riihela’s blog there is a post with some useful comments about some Finnish sources of information about chickweed and some suggestions as to how the misleading notion that chickweed could be used as a mordant might have come about. The post is written in Finnish but there is an English translation underneath. Some of the comments on Leena’s post are also interesting.

 

If you click on the link to “Riihivilla” on the right hand side of my blog, you will find a link there to Leena’s blog.

 

Also, in a German dyeing book, “Farben aus der Natur” by Gretel Fieler, published in 1981, I have found a reference to a recipe from 1817 in a German dyeing book by Johann Hinrich Ehlers, in which he mentions the use of chickweed plus alum as a mordant used with logwood for dyeing shades of blue. However, although chickweed is mentioned in the mordanting paragraph, alum is added to the chickweed solution before the wool is mordanted, so it is the alum which is the true mordant here, not the chickweed. I think it is possible that the chickweed may have been used for its potash content, which could shift the colour from the logwood from purple towards blue. It is interesting to find such an old recipe, which is almost identical to those mentioned in the more recent books from so long ago.

 

Now I must find the time to try out this recipe with chickweed, alum and logwood, to see how it compares with the colours from logwood when chickweed is not included. But before I do anything else, I must continue working on my new book.

 

Chickweed as mordant?

Sunday, February 10th, 2013

 

Before anyone gets too excited, I’m afraid the answer to the question posed in the title would seem to be “No, probably not.” So where did I get the idea that chickweed might be used as mordant?

 

Last year I read an interesting article in “The Journal for Weavers, Spinners and Dyers” about natural mordants. The article was written by Krista Vajanto, who teaches textile history at the University of Helsinki, Finland and is researching Iron Age Finnish textiles. Among the details of the better-known natural mordants (rhubarb leaves, tannin, aluminium from clubmoss) was a mention of chickweed. The positioning of the comment gave the impression that chickweed might also be an aluminium accumulator and if this were the case it would, of course, be extremely useful for dyers who want to use only natural mordants from plants.

 

Chickweed (Stellaria media) is a common weed in many gardens (although, rather annoyingly, not in my garden) and apparently several Finnish dyeing books from the 20th century mention using chickweed as a “natural mordant”.  Unlike clubmoss, chickweed is not rare and could therefore be used freely for dyeing, so I decided to do some experiments to test its potential as a “natural mordant”. The article stated that chickweed should be used fresh but unfortunately it proved impossible to locate any fresh chickweed. So, as I usually extract aluminium from dried, rather than fresh, clubmoss, I thought it ought to be possible to use dried chickweed, which I bought from a supplier of dried herbs.

 

I treated the chickweed in exactly the same way as I treat dried clubmoss when I extract aluminium from it and then I used the chickweed solution as a mordant in the same way.

 

I then made a dyer’s broom dye bath and dyed skeins treated with clubmoss and chickweed and also alum-mordanted and unmordanted skeins in the same dye bath. The results were interesting. The alum-mordanted skein and the skein treated with clubmoss dyed a very similar yellow, indicating the presence of aluminium in the clubmoss. The skein treated with chickweed and the unmordanted skein dyed to almost exactly the same shade of pale yellow, which suggested that there was no aluminium present in and extracted from the chickweed. Although I wasn’t able to use fresh chickweed and I admit I might have got different results had I been able to do so, I have so far come to the conclusion that chickweed is unlikely to prove useful as a natural mordant. Indeed, I feel certain that, had it been useful as an alternative to alum, dyers would have been aware of that fact long ago. However, I will reserve my final judgement until I have managed to try the same experiments with fresh chickweed, just in case.

 

So how did this belief originate? I have come to the following conclusions. Firstly, the term “mordant” tends to be used very loosely in some literature and often seems to mean “anything that can be used as a base for other dyes or as an addition to a dye pot”. I suspect that, when applied to chickweed, the term “mordant” was being used in that rather loose sense. I believe it is possible that, in situations where it might have been difficult to obtain more expensive dyes or chemical mordants, plants such as chickweed, which grow abundantly as weeds and give a light yellow colour, might have been used as a base for more expensive or difficult to obtain yellow dyes, in order to reduce the quantity required of the more precious dyestuff. So the belief might come about that, if chickweed “helped out” with yellow dyes, it might also have a similar effect with other dyes.

 

But I’m afraid I feel it is unlikely that chickweed has ever truly been, or indeed is ever likely to become, an alternative “mordant”. Unless, of course, experiments with fresh chickweed suggest otherwise but first I must find some.

 

chickweed mordant

 

The photo above shows samples dyed with dyer’s broom (Genista tinctoria)

From the top: alum mordant, clubmoss mordant, chickweed base, no mordant

New Natural Dye Extracts in Liquid Form

Tuesday, January 8th, 2013

 

Just before Christmas I noticed some new dye extracts in liquid form on the D T Crafts website (see link on the right) and, as these are new to me, I ordered some. The dyes are called Botanical Colors Aquarelle and have been certified as compliant with the Global Organic Textile Standard. So my first dyeing project for 2013 has been to try them out.

The dye extracts offered in liquid form are Madder, Lac, Himalayan Rhubarb, Cutch and Saxon Blue. These dyes come with clear instructions and are simplicity itself to use, as they are just added to the dye bath water and stirred in.  They work equally well on all natural fibres, although Saxon Blue tends to produce paler shades on vegetable fibres. A little goes a long way, so I feel they are reasonably priced.

 

The photos below show some of the colours.

 

lac

 

LAC: The wool skein on the left was mordanted with alum, the central skein was unmordanted and the skein on the right was another unmordanted skein, this time over-dyed in Saxon Blue. The skeins are shown on unmordanted silk fabric dyed in the exhaust dye bath.

 

rhubarb, madder, lac etc 005

 

HIMALAYAN RHUBARB ROOT: The upper two skeins were mordanted with alum and the lower two skeins were unmordanted. The skeins are shown on unmordanted silk fabric, dyed in the exhaust dye bath.

 

rhubarb, madder, lac etc 017

 

SAXON BLUE: This liquid indigo is an improved formulation of Saxon Blue, which was first created in the 18th century. It is used in exactly the same way as the other liquid dyes, so there is no need to prepare a vat using stock solutions or reducing agents and the blue liquid can be added to other dye baths, so for example green can be produced by adding some Saxon Blue liquid to a yellow dye bath. All the samples shown are unmordanted and the skein on the right shows the effect of the dye on grey wool.

 

rhubarb, madder, lac etc 012

 

MADDER: The two wool skeins on the left were mordanted with alum and the two skeins on the right were unmordanted. The skein on the extreme right shows the effect on grey wool. The skeins are shown on unmordanted silk fabric dyed in the exhaust dye bath.

 

As the photos indicate, the colours from these dyes are lovely and there is considerable potential from just these few dyes for creating further colours by varying the strength of the solution and by over-dyeing or colour mixing. If the Saxon Blue liquid extract lives up to expectations, it should make many compound colours so much easier to achieve.  I feel very enthusiastic about these new liquid extract dyes and look forward to experimenting further with them.

 

 

Sawwort (Serratula tinctoria)

Friday, August 24th, 2012

 

Sawwort is a perennial plant with purple thistle-like flowers and serrated-edged leaves. It produces colours similar to those from weld (Reseda luteola) and, as with weld, the main dye component of sawwort is luteolin. According to Dominique Cardon (Natural Dyes 2007), sawwort has been used in Europe since the Middle Ages, especially in areas where weld was not harvested, and in Tuscany during the 14th and 15th centuries it was as highly regarded as weld.

Sawwort is a dye plant I have wanted to try for a long time but had not been able to find, although it is native to Britain and grows wild here. Recently I discovered a supplier of native wild plants (www.naturescape.co.uk), from whom I bought several sawwort plants last Autumn. Sawwort should not be harvested for dyeing until the second year but as usual I was too impatient to wait until next year, when my plants would have been more mature.

I used about 100% dyestuff to weight of fibres and this produced a dyebath strong enough to enable me to use the same dyebath 3 times for successively paler yellows. The results were very pleasing and I shall probably order more sawwort plants this Autumn, especially as sawwort is a perennial plant and should prove more reliable as a garden plant than weld, which is sometimes not easy to grow. (This year I had no self-seeded weld plants and the seeds I sowed in the Spring germinated but the seedlings failed to develop because of the wet weather and are still no bigger than they were in April.)

The photo below shows, from left to right: alum mordant x 3 samples, alum mordant & iron modifier x 2 samples, alum mordant & copper modifier x 2 samples. The first 3 samples show a range of yellows from (a) the original dyebath, (b) the first exhaust dyebath & (c) the second exhaust dyebath

Dyes of the Celts

Wednesday, May 2nd, 2012

The word “Celt” is apparently derived from the Greek word “keltoi”, meaning “barbarian”, and is used to describe tribal societies in Iron-Age and Roman-era Europe, who spoke Celtic languages and were loosely tied by similar language, religion and cultural expression.

In preparation for a workshop on Celtic Dyes that I led recently at Fishbourne Roman Palace near Chichester, I have been doing some research into the dyes that may have been used by the Celts in Iron -Age Britain (c.600BC – 50AD).

The proto-Celtic culture in Europe was the Hallstatt culture (c.800BC – 450BC), named after the site of rich grave finds at Hallstatt in Austria. This culture then spread over much of Europe, into Britain, France, central Europe, the Iberian Peninsular and Northern Italy. The conditions in the Hallstatt salt mines, where the graves were discovered, meant that the textiles found there were relatively well preserved and analysis carried out on some of them gives an indication of the dyes and techniques used by the Hallstatt Celts.

Woad and weld were identified on textile fragments and also tannin, although it is not possible to identify the precise source of this tannin. Other unidentified yellow dyes were also found (perhaps sawwort or chamomile) and there is a possibility that lichen purple may also have been used. The red dyes analysed are interesting – there was no trace of any of the madder-type sources of red but some indication of unidentified insect dyes, possibly Polish or Armenian cochineal, and also of kermes. Both white and naturally pigmented wool was dyed and there is evidence of over-dyeing to create further shades. The issue of mordants is problematic; iron and copper were identified on several fragments and aluminium was identified on one or two fragments. However, it is possible that these minerals were present because of contamination within the salt mine, rather than because they were intentionally used in dyeing.

For my experiments I used white and naturally-coloured brown and grey wool. As I think it is unlikely that Iron-Age dyers in Britain would have had easy access to mineral alum. I decided not to use an alum mordant. Some samples were pre-treated in tannin from oak bark and others were unmordanted. The dyes I used were: weld (Reseda luteola), hedge bedstraw (Galium mollugo), lichen purple (Ochrolechia tartarea), oak bark (Quercus spp.) and woad (Isatis tinctoria). Although there was no trace of Galium spp. dyes on the Hallstatt textiles, I felt it would be historically correct to use native bedstraws in my experiments, as there is evidence from elsewhere that these plants were used for dyeing in the Iron-Age. Some samples were then over-dyed in woad and some samples were also treated in an iron-water solution after dyeing.

 

Some of the results of Celtic dye experiments.

The top row shows the colours from lichen purple with vinegar added to the dye-bath (except for a couple of woad samples on the extreme right). The second row shows lichen purple colours, without vinegar added to the dye-bath. The third row shows the colours from hedge bedstraw (Galium mollugo). The fourth row shows the colours from weld (Reseda luteola) and the bottom row shows the colours from oak bark. On each row some of the samples have been over-dyed in woad.

The Romans commented on the brightness of the clothing of the native Britons and the results of my experiments indicate that, even without alum as a mordant, it was certainly possible to produce bright colours in the Iron Age. The Celts also produced fabrics patterned with checks, stripes and plaids and this must have added to the impression of brightness.

Memories of Summer

Friday, December 9th, 2011

As the colder weather sets in and Christmas approaches, I find my thoughts returning to the warm, sunny days of Summer. One of my most enjoyable activities this Summer was introducing my 3-year-old granddaughter, Milly, to the delights of using plants for colour and this proved very popular. As I wanted to avoid any confusion between “dyeing” and “dying”, I decided to call our experiments “making colours for white wool”.

We collected onion skins, dyer’s broom tops, dyer’s chamomile flowers, dahlia flowers and marigolds (Calendula) and we also used some of the frozen viola petals (as used for the ice-flower experiments described in an earlier post). We put these into glass jars, together with a skein of alum-mordanted wool and we added an iron spike to the jar with the marigold flowers. These jars were then left in the sun and Milly regularly checked the progress of the colour on the skeins each time she visited us. When she was satisfied with the colour on each skein, she pronounced the experiment finished and we then rinsed, washed and dried the skeins. She now has a small sample of each colour in her own personal scrapbook.

I am looking forward to introducing Milly to more dyeing experiments next Summer, when the weather is warm enough for working outside.

This photo shows some of the experiments in progress. From left to right: frozen viola petals, dahlia flowers and onion skins

This photo shows the results of our experiments. From left to right: dyer’s chamomile, frozen viola petals, dyer’s broom, marigolds (plus iron spike), dahlia flowers and onion skins

Anglo-Saxon dyes – woad

Saturday, August 27th, 2011

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

  

Anglo-Saxon colours from oak leaves and acorns

Monday, August 15th, 2011

Although walnut hulls are often the dye of choice for browns, I decided to use oak leaves and acorns in my tests, because the walnut tree is not native to Britain and walnuts may not have been widely available during the early Anglo-Saxon period. I harvested the acorns and oak leaves in early Autumn and dried the leaves before use. As oak leaves and acorns are rich in tannin, no mordant is needed.

The first photo below shows colours from oak leaves. An alum or clubmoss mordant produced slightly more yellowish colours and a tannin mordant made the colours deeper. An alkaline modifier increased the depth of these colours. Mid-grey was achieved on unmordanted fibres modified in iron and a very dark grey was achieved on tannin-mordanted fibres modified in iron.

The second photo below shows colours from acorns. The comments on mordants and modifiers, made above for oak leaves, also apply to acorns. The  dark grey was achieved on tannin-mordanted fibres modified in iron.