Natural Dye (Part 5 of 6):Categories Of Natural Dyes

 

Substantive dyes Whereby no mordants (dye fixes) are required to set the colours.
Vat dyes Whereby fixing the colours involve the oxidization process.
Mordant dyes Whereby the dyes require the use of an additive, usually some form of mineral, to set the colours.
Method of dyeing each category
Substantive Dyeing

For substantive dyeing, the general process is as follows:

  1. Pre-clean the material.
  2. Extract the dye wanted from plant parts or bugs.
  3. In a big pot, combine the dye extract with some water. Meanwhile, soak the material in some warm water. It is important that the pot be big enough so that the material can swim freely in it. It helps in getting an even colour.
  4. Slowly, simmer the dye. (Take note that when dyeing silk, it should not be heated past 85°C (180°F) as it can lose its sheen) Put the material to be dyed in. Boil until the desired colour is obtained, while stirring once in a while, or it can be left overnight without heat to obtain a darker colour. The longer it is soaked, the darker the colour will be. A good thing to keep in mind is that the colour will be much lighter upon rinsing, so the material should be a few shades darker than desired when lifted from the pot.
  5. Once it is done, the fabric should be rinsed with plenty of cold water. Change the water as often as needed. If wool is the dyed material, it should be handled gently as it can shrink. Hang to dry.
Vat Dyeing

Any garment, cloth or threads that have been naturally dyed indigo uses this method of dyeing. The indigo dyeing process is extremely unique as the dye by itself, does not naturally exist. It requires a process of oxidizing, deoxidizing, fermentation and re-oxidizing to get the colour. Besides that, it does not need a mordant. Indigo is not water soluble as well, requiring an alkali to be dissolved.

An indigo vat can store indefinitely as well. The ingredients just need to be added when the amount of indigo in the dyebath is low. After dyeing, the vat should “rest” for at least 24 hours to let the indigo deoxidize. This is done to regain the colour of the indigo.

 

Below are the steps to create a fermented indigo dye:

  1. Put 9 litres of water, 60g of madder, 22g of indigo, a tablespoon of soda ash and 20g of bran with 550ml of wood ash lye in an enamel, porcelain or stainless steel pot. This will be your vat. An aluminium pot is not recommended as they tend to rob the indigo of the rich colour it is famous for. Traditionally, just urine and indigo is used to create this fermented vat.
  2. Keep the vat in a warm place (around 40°C) and let it ferment. Make sure the vat is covered and the liquid reaches no less than 5cm from the pot cover. Stir it daily to allow the ingredients to combine together. The stirring must be done in a way that does not incorporate air to the vat.
  3. The dye should be ready in a week. If it is renewed (i.e. more ingredients are added in proportion to the vat when the dye begins to dye only light colours), it would take about 4-5 days.
  4. The dye is ready when a coppery film forms on top of the dye. When lifted in a glass jar, the liquid should appear green. (it is known as indigo white at this stage) Do not worry, as once the dyed material comes in contact with air, the dye oxidizes and becomes the rich indigo we know.

 

 

The coppery film

The ready to use dye. Note the green liquid. It will oxidize upon contact with air as shown by the blue froth.

 

 

 

 

 

 

 

 

 

 

 

How do you dye with indigo?

  1. Make sure the cloth is clean. Even if it looks clean, wash it still! Any oil or residue that is invisible to the naked eye will not make the dye adhere to the cloth.
  2. Air is BAD for the dye. So, the material to be dyed must be soaked in warm water (about the same temperature as the pot, 40°C) before being dyed. Another method is to wring the material while it is dry, dunk it slowly in the pot and let go of it.
  3. While lowering the material into the dye, it needs to be done as slowly as possible to ensure as little air as possible gets into the dye.
  4. Once the material is in the dyebath, squeeze the material. This is to ensure that the dye penetrates the material. Make sure you do not break the surface of the dye as air might get in. After a few minutes, wring the cloth close to the surface of the indigo to prevent minimal air entering the dyebath.
  5. Once wrung, dry the cloth. To produce a deep shade of indigo, the process has to be repeated; sometimes up to 50 times!
  6. The shade should be a few times darker than the ideal shade. This is because the subsequent rinsing will rinse out extra dye and will turn the cloth about 2-3 shades lighter.
  7. Rinse well and let the material dry.

 

 

Putting the white cloth into the vat.

Squeezing the excess dye out.

The greenish-yellow freshly dyed cloth.

After a while, it oxidizes to form indigo.

 

 

 

 

 

 

 

Mordant Dyes

Mordants are dye fixtures. It means that they act as a substance that “opens up” the material, allowing the absorption of the dye. The process of mordanting is usually done before putting the cloth in the dyebath. Some have reported success with utilizing this process during and after but the results vary. pH is a very important factor in mixing a mordant. Cellulose fibre such as linen needs an alkaline pH for the mordant to work and to improve colour fastness. (Resistance of the fabric to fading) However, a combination of tannin-alum-tannin works best for cellulose fibres. On the other hand, animal based fabric such as wool needs an acidic pH to work well.

The cores of mordanting are usually metals like tin and chrome. Hence, in powder form, mordants are highly toxic. Mordant pots must NEVER be used for cooking. Gloves and masks should be used when handling them. In addition, if dyeing at home, this process should always be done outdoors. However, there are mordants that are non-toxic such as salt and vinegar.

 

 

Below is a list of some mordants and their effects.

 

Alum (Aluminium Potassium Sulfate)

   Doesn’t give colour but helps colour bond to the material.

 

Copper (Copper Sulfate)

   It gives a slight green to aqua tint.

 

Iron (Ferrous Sulfate)

   Makes colours darker or gives a grey hue.

 

Chrome (Potassium Dichromate) – toxic!

   Gives a yellowish tint.

Tin (Stannous Chloride)

   Brightens colours.

 

Tannin

Doesn’t give colour but helps colour bond to the material; especially cellulose fibres.

 

 

How is a mordant mixed?

Alum – Use about 10-25% of alum per weight of dyeing material with ¼ of the alum’s weight in cream of tartar. Dissolve in some hot water and then mix it with lots of cool water.

Tannin – 10% of tannic acid per weight of dyeing material is dissolved with a small amount of hot water and then mixed with lots of cool water.

For others – Mix the mordant in some hot water and then mix it with lots of cool water.

 

What is the timing for mordanting materials?

 

Material

Method

Yarns

It should be simmered in the mordant for at least ¾ of an hour. 

Cotton

It should be soaked several hours to 24 hours in the mordant and then simmered for ¾ of an hour. A recipe of alum-tannin-alum is used, where it is first soaked in alum, dyed with the colour and tannin and put in alum again before the few final dips of colour. 

Silk

Soak it for 24 hours in the mordant and then simmer for ¾ of an hour. Never go above 85°C (180°F) as it will lose its natural sheen. It needs an acid bath for the dyes to attach therefore; a rinse of weak vinegar will do the trick. Let it cool and soak in water for a day. 

Wool

Simmer it for an hour in the mordant, let it cool and rinse with lots of water. 

Coarse fibres

(such as linen and ramie)

Fibre is soaked for a few to 24 hours in the mordant and simmered for at least an hour. Leave it to cool for a day in the mordant. 

 

 

What is the mordant dye process?

  1. Pre-clean the material and dry it.
  2. Mix the mordant. Soak the cloth for as long as needed.
  3. In a big pot, combine the dye extract with some water. Meanwhile, soak the material in some warm water. It is important that the pot be big enough so that the material can swim freely in it. It helps in getting an even colour. Slowly, simmer it. (Take note that when dyeing silk, it should not be heated past 85°C (180°F) as it can lose its natural sheen). Put the material to be dyed in. Boil until the desired colour is obtained, while stirring once in a while, or it can be left overnight (without heating) to obtain a darker colour. The longer it is soaked, the darker the colour will be. A good thing to keep in mind is that the colour will be much lighter upon rinsing, so the material should be a few shades darker than desired when lifted from the pot. Sometimes, a mordant is added to the dyebath or added to the dyebath during the last few dips.
  4. Once it is done, rinse it in a mordant. After that, the fabric should be rinsed with plenty of cold water. Change the water as often as needed. If wool is the dyed material, it should be handled gently as it can shrink. Hang to dry.

 

Here is an example of mordant dyeing:

Mordanting the scarf in a salt solution.

Boiling the dye (elderberries) and straining it.

Simmering the rinsed mordanted scarf in the dyebath.

The finished scarf.

 

 

 

 

 

 

 

Continue To Part 6: Other Methods Of Natural Dyeing




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One Response to “Natural Dye (Part 5 of 6):Categories Of Natural Dyes”

  1. Kayleigh Mcdonnall says:

    Is the tincture just as effective as the raw pine pollen

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