Dyeing

The next step in the process is to dye the fibres. This booklet will explain the dyes to produce the best primary colours (red, yellow and blue) as from these the whole spectrum of colours can be made.
Detailing what each dye stuff is, the plant it is from, how it is produced and the dyeing process.

Madder - Red

Also called Rubia Tinctorum, madder is in the same plant family as coffee. It has been shown to have been used as a dye for over 5000 years.
Colour - Reds. A range of reds from orangey reds to vivid reds depending on the roots. Where they are grown, the mineral content of the water in the dye bath, the temperature of the dye bath and the ratio of dye stuff.
What is it? -Native to Asia this plant has been used for dyes and trade since ancient times.
It has since been cultivated globally for the red dye its roots produce.
Growing it - Hardy to the UK. It likes mildly acidic/neutral/mildly alkaline soil. It can grown in semi-shade/no shade. Grows in hedge rows and cultivated beds. Well fertilized and limed soil produces stronger red pigments
Could it be farmed in the UK? - Could potentially be farmed in the UK as it will grow in these conditions. Could be planted in hedge rows and harvested. Naturally seeding itself to continue the growth of the crop if left to seed.

How the dye is extracted? - Plants need to grow for minimum 3 years, with the best colour being extracted from 5 year old plants.
To use the plant pull it up and leave the roots to dry for a couple days.
Then the roots can be either used fresh to dye or dried to a more concentrated form.
Using the dye -
100g of fresh root is approx equal to 14g of dried roots.
1 - Fill a pan with water and bring to a low simmer (approx 85 °C)
2 - Weigh the dry wool to be dyed and put equal weight of dye stuff to this into a net bag and seal it
3 - Put the net bag into the dye bath and mix
4 - Add the wool and top up with water so the wool can move freely
5 - Keep the water around 80 °C for 10 minutes, string the wool intermittently
6 - Take the wool out and rinse it, wash with washing up liquid to get rid of excess dye
7 - Leave to dry

The weight of dye stuff needed, temperature of the water and length of time left in the dye bath can all be varied to create a spectrum of reds. From pale pinks to deep reds. The red wool can also be then combined with a yellow or blue dye bath to create the range of secondary orange and purple colour spectrum.
The strength of the dye can be controlled to create specific colours. Along with the other 2 variables.

Weld - Yellow

Evidence of weld being used as a dye have been found in ancient Roman art.
Colour - Lemon yellows. Around 3g of calcium carbonate can be added during the dyeing process to increase the potential vibrancy of the yellow.
What is it? - Also called dyer’s rocket, weld can often be called a weed as it likes to grow on waste soil like industrial ground. The leaves and flowers of the plant are where the dye can be extracted from.
Growing it - Likes well drained slightly alkaline soil. Chalk or loam or sand soil. Full sun to partial shade
Could it be farmed in the UK? - It could potentially be grown in abandoned industrial areas or waste land around the UK as it is hardy to our climate.
How the dye is extracted? - When the plant is flowering and green it is harvested. The steams are taken out as these do produce much dye. Dyeing with fresh plants produce the strongest dyes. The plant can also be dried in a green house and used .
300g of fresh weld is equal to approx 50g of dried weld.

Using the dye? - The same process as explained above for madder dye.
The weight of dye stuff needed, temperature of the water and length of time left in the dye bath can again all be varied to create a spectrum of yellows. The yellow wool can also be then dipped into a red or blue dye bath to create the range of secondary orange and green colour spectrum.
The strength of the dye can be controlled to create specific colours. Along with the other 2 variables.

Indigo - Blue

Indigo dyes have had influence on the development of society since early indus valley civilizations. Being almost the only way blue pigment could be obtained until the invention of synthetic dyes.
Colour - Depending on the concentration of pigment dyed with colours from deep blues to pale sky blues can be obtained.
What is it? - Indigofera tinctoriais a plant that is thought to have originated from Asia or northern Africa. The leaves of the plant are harvested then left to ferment for 3 days in water for the pigment to release from the plant. Then the liquid is mixed with natural salts to create the concentrated indigo pigment.
Growing it? - It requires full sun and is mostly hardy in the UK but it could require greenhouses to grow most effectively. Likes well drained sandy/chalky/clay soil. It is a deciduous shrub and can grow up to 2m tall.
Could it be farmed in the UK? - Yes it could be but would potentially require more set up than the madder and weld plants as indigo grows best in a green house in the UK.

Using the dye - Making indigo dye vats requires a few more ingredients than the red or yellow vats. Due to it being a fermentation vat that needs to be de-oxygenated. The process of creating an indigo dye vat are:
1 - In a small amount of water mix indigo powder and an alkaline such as soda ash. With a ratio of 2:1 of soda ash to indigo powder
2 - Then add approx 7 litres of water to the vat and heat to around 45 °C. Checking the pH of the vat, which should be around 9/10 p
3 - Maintain the vat at a temperature around 40 °C.
4 - Then add the reducing agent to the vat to remove the oxygen. Such as around 15g of thiorea dioxide
5 - Stir the vat, taking care not to disturb it too much and introduce any oxygen into it, check the pH keeps to 9/10 pH and leave for around an hour
6 - After an hour the vat should be yellow/green with a coppery sheen dark blue scum on top. This means the vat is ready to use
7 - Wet whatever is going to be dyed (this avoids adding any oxygen to the vat)
8 - Dip it into the vat and leave fully submerged for around 5 minutes for an even strong dye
9 - The vat can continuously be used to dye more fibres but each time something is dipped into it the colour will become lighter. This is how sky blues and other shades can be achieved
The blue wool can then be dipped in a yellow or red vat to create greens and purples on the whole spectrum of these colours depending on intensity of the dyes.