Textile Notes related to fiber, yarn, fabric knowledge, spinning, weaving, processing, projects, knitting, Indian Traditional Textiles and denim manufacturing
Natural dyes, derived from plant sources or other natural materials, are known for their vibrant and diverse color palette. However, compared to synthetic or chemical dyes, natural dyes generally exhibit lower colorfastness. Here are some reasons why natural dyes may not be as colorfast:
Chemical Composition: Natural dyes are composed of complex mixtures of organic compounds present in plant materials. These compounds can be sensitive to factors such as light, pH, and washing, leading to color fading or changes over time.
Lack of Fixation Agents: Natural dyes often require the use of mordants or fixatives to enhance their colorfastness. Mordants help bind the dye to the fabric fibers, improving its resistance to fading. However, the availability and effectiveness of mordants for natural dyes can vary, resulting in varying degrees of colorfastness.
Light Sensitivity: Many natural dyes are sensitive to light and can fade when exposed to prolonged sunlight or artificial light sources. This light sensitivity is attributed to the degradation of the color molecules present in the dyes.
pH Sensitivity: Natural dyes can be sensitive to changes in pH levels. Factors such as the alkalinity or acidity of the environment or the washing detergent used can influence the stability and colorfastness of natural dyes.
Washing and Care: Natural dyes can be more susceptible to color loss or bleeding during washing compared to synthetic dyes. Harsh washing methods, including the use of strong detergents or high temperatures, can accelerate color fading or bleeding.
Variability in Plant Sources: Natural dyes obtained from different plant sources or batches can exhibit variations in their dye composition and quality. This variability can impact colorfastness, as different dye components may have different stability and resistance to fading.
Despite the challenges with colorfastness, natural dyes are still valued for their unique and environmentally friendly qualities. There are ongoing research and efforts to improve the colorfastness of natural dyes through advancements in dyeing techniques, mordanting processes, and the development of natural dye extracts or formulations.
To enhance the colorfastness of natural dyes, certain steps can be taken:
Pre-treatment and Mordanting: Proper pre-treatment of fabric and the use of suitable mordants can improve colorfastness by enhancing the binding of natural dyes to the fibers.
pH Control: Maintaining a stable pH environment during dyeing and subsequent washing can help preserve the color intensity and stability of natural dyes.
Avoidance of Harsh Washing: Gentle washing techniques using mild detergents, cold water, and minimal agitation can help minimize color loss or bleeding.
Protection from Light: Limiting exposure to direct sunlight or storing natural dyed textiles in dark or shaded areas can help reduce color fading caused by light.
While natural dyes may have lower colorfastness compared to synthetic dyes, they offer unique aesthetic qualities and can be appreciated for their sustainable and eco-friendly nature.
Traditional Ways of Printing with and Extracting Indigo
Indigo has a special place in the history of textiles. It is not merely a colour; it is a complete craft process. The blue that we see on cloth does not come easily. It has to be coaxed out of the plant, transformed through fermentation or chemical reduction, allowed to enter the fibre, and finally brought back to blue through contact with air.
This is what makes indigo different from many other natural dyes. Many dyes are applied in a dissolved form and then fixed to the fibre with suitable mordants or process controls. Indigo, however, is naturally insoluble in water. To use it for dyeing or printing, the dyer must first convert it into a soluble reduced form. Only then can the colour enter the cloth or yarn. After exposure to air, it oxidizes and becomes blue again.
The traditional knowledge around indigo therefore combines plant science, chemistry, patience, and skilled hand practice. This article explains the traditional extraction of indigo, the making of an indigo vat, the use of indigo in printing, and the logic behind the colour change that makes indigo so fascinating.
The beauty of indigo lies in its unusual dyeing behaviour. Indigo pigment is not readily soluble in water. This means that the blue pigment, in its ordinary oxidized form, cannot simply dissolve in a dye bath and enter the fibre like many other dyes.
To dye cloth or yarn, indigo must first be converted into a reduced soluble form called leuco-indigo. This form can penetrate the fibre. When the material is removed from the vat and exposed to air, oxygen converts the reduced form back into insoluble blue indigo. The colour therefore develops through oxidation.
A simplified way to understand the process is:
\( \text{Insoluble Indigo} \rightarrow \text{Soluble Leuco-Indigo} \rightarrow \text{Insoluble Blue Indigo on Fibre} \)
This is why indigo dyeing often looks almost magical to an observer. The cloth may come out of the vat looking yellowish, greenish, or dull. Then, as it meets the air, it slowly turns blue. The colour appears before the eyes, but the transformation is actually a controlled chemical process.
Suggested Visual 1: Indigo transformation map — from leaf to precursor, pigment, vat and blue fabric.
Extracting Indigo from Fresh Leaves
Traditionally, indigo extraction begins with fresh indigo leaves. The leaves are steeped in water, often in a tank or cistern, for several hours. In some descriptions, the leaves are left for about twelve hours, though the exact time depends on the climate, the condition of the leaves, and the local method.
During steeping, the leaves begin to decompose. Enzymes and microorganisms act on the natural compounds present in the leaves. The important compound in the leaf is indican, which is colourless. Through hydrolysis, indican breaks down into indoxyl and glucose.
This is an important point. The blue pigment is not present in the fresh leaf in its final usable form. The leaf contains a precursor. The blue colour is created only after a sequence of chemical changes.
Once the leaves have steeped sufficiently, they are removed from the liquid. The liquid is then transferred into another tank or vessel and stirred, beaten, or agitated vigorously. This introduces oxygen into the solution. In the presence of oxygen, indoxyl molecules combine to form indigotin, the familiar blue pigment of indigo.
The blue pigment is insoluble and gradually settles at the bottom of the vessel as a blue sludge. This sludge is then collected, filtered, drained, and dried. After drying, it may be shaped into cakes, blocks, balls, or squares. In this compact form, indigo becomes easier to store, transport, sell, and use.
Thus, the journey from green leaf to blue pigment involves three broad stages: steeping of the leaves, oxidation of the extracted liquid, and collection and drying of the blue pigment. This simple-looking process hides a great deal of experience. The artisan must know when the leaves have steeped enough, how vigorously the liquid should be stirred, when the pigment has settled, and how to dry and store it properly.
Another Traditional Method: Crushing the Leaves
In another traditional method, fresh leaves are crushed and compacted to form a sticky paste. This paste is drained and shaped into balls. Such methods are useful when the dye material has to be preserved, stored, or transported in a convenient form.
The final form of indigo may vary from region to region. In some places, it is made into cakes; in others, into balls or blocks. These forms are not only practical but also reflect local tradition, available tools, and the needs of dyers and printers.
Making an Indigo Vat
To dye cloth or yarn with indigo, the blue pigment has to be converted into a soluble form. This is done in an alkaline reducing vat. The vat is the heart of indigo dyeing, because it changes insoluble indigo into a form that can enter the fibre.
Indigo vats are sometimes buried in the ground. This is done because earth and sand act as natural thermal insulators. They help maintain a more constant temperature in the dye bath. Temperature control is important because the behaviour of the vat depends on the balance of alkalinity, reduction, and microbial or chemical activity.
In traditional vats, the water may be filtered through wood ash. Wood ash contributes alkalinity and may also help reduce froth and suspended particles. Depending on the local practice, materials such as lime, sodium carbonate, molasses, starch, alcohol, or other organic substances may be added. Some vats are based mainly on fermentation, while others use stronger chemical reducing agents for quicker results.
The dyer watches the vat carefully. The colour of the liquid, smell, surface bloom, froth, temperature, and behaviour on the yarn or cloth all provide clues. In many natural dyeing traditions, the vat is treated almost like a living system. It has to be maintained, fed, revived, and used with care.
Suggested Visual 2: Cross-section of a traditional indigo vat showing reduction in the vat and oxidation in air.
Dyeing with Indigo
When cloth or yarn is dipped into the reduced indigo vat, it does not immediately appear deep blue. It may come out yellowish, greenish, or pale because the indigo is still in its reduced soluble form.
The colour develops when the material is exposed to air. Oxygen from the atmosphere acts on the reduced indigo. The leuco-indigo oxidizes and turns back into insoluble blue indigo inside and on the surface of the fibre.
For darker shades, the same cloth may be dipped and oxidized several times. Each dip adds more depth. The skill lies in controlling the number of dips, the strength of the vat, the time inside the vat, and the oxidation time between dips.
Indigo Printing in Machilipatnam
Indigo is not only used for dyeing; it is also used for printing. One traditional example comes from the printing practices associated with Machilipatnam. In printing, the artisan needs a paste rather than a simple liquid dye bath. The paste must have the right body so that it can be applied clearly to the cloth using blocks or other printing tools.
If the paste is too thin, the design may spread and lose sharpness. If it is too thick, it may not print evenly. Therefore, the consistency of the printing paste becomes a matter of craft judgement. The printer understands the paste through hand, eye, and experience.
A traditional description of the process may be understood as follows. Rice flour is mixed with water and heated to make a starchy paste. A cake of indigo is ground into powder. About two hundred and fifty grams of indigo powder may be mixed with a small quantity of castor oil. To make the dye usable quickly, caustic soda and hydrosulphite powder are added.
The ingredients are combined in stages. The starch is added last and stirred until the paste reaches the correct consistency for printing — not too runny and not too thick.
Here, each ingredient has a role. Indigo provides the colour. Caustic soda creates the alkaline condition. Hydrosulphite acts as a reducing agent, converting indigo into a usable reduced form. The starch gives body to the paste. Castor oil may help in grinding, dispersion, and smoothness of the paste.
This is a good example of how traditional craft and practical chemistry meet. The printer may not describe the process in laboratory language, but the working knowledge is precise. The artisan understands the behaviour of the paste through observation, repetition, and experience.
Fixing and Washing the Printed Cloth
After printing or dyeing, the cloth is dried for much of the day. It may then be immersed in a lime solution, followed by an iron sulphate solution. After this, it is rinsed several times, sometimes including a rinse in boiling water.
These after-treatments help complete the process and remove unfixed material. By this stage, the colour becomes more stable. Proper oxidation, washing, and finishing are important for developing good fastness.
A well-processed indigo cloth should not fade quickly in sunlight or washing. However, indigo also has a special surface character. In many fabrics, especially denim and other heavily dyed textiles, indigo may gradually rub, soften, and fade with use. This is part of its charm. But in traditional printing and dyeing, the aim is still to obtain a clear, well-developed, and reasonably fast colour.
The Chemistry Behind the Craft
The indigo process can be understood through a simple sequence. The leaf contains indican. During steeping, indican is hydrolysed to indoxyl. On exposure to oxygen, indoxyl forms indigotin. During dyeing, indigotin is reduced in the vat to leuco-indigo. On exposure to air, leuco-indigo oxidizes back into blue indigo on the fibre.
This sequence explains why indigo requires so much process knowledge. The dyer has to move the colour between different chemical states. The blue pigment must first be formed from the plant, then reduced to become soluble, then oxidized again to become blue and fixed in the cloth.
This is why indigo dyeing is often called both an art and a science. The artisan is controlling chemistry through traditional practice.
Suggested Visual 3: Full process flow — extraction, vat preparation, printing, oxidation, washing and finishing.
Sashiko and Indigo Textiles
The notes also refer to Sashiko, a Japanese stitching tradition. Sashiko involves placing several layers of cotton fabric together and sewing them with running stitches, traditionally using cotton or hemp yarn.
Although Sashiko is not a method of extracting indigo, it is strongly associated with indigo-dyed textiles in Japan. The combination of white running stitches on deep blue cloth became visually distinctive. In this way, indigo was not only a dye but also part of a larger textile culture involving repair, reinforcement, decoration, and everyday use.
Motifs in Indigo Printing
Traditional indigo printing is not only about chemistry. It is also about design. Motifs carry local vocabulary, memory, and identity. The notes mention motifs such as Dogga and Shakka, with Shakka possibly described as a wheel-like motif.
Such motif names should be verified regionally because spellings and meanings can vary across craft traditions. Many textile motifs change names as they move between languages, regions, workshops, and communities.
Why Indigo Matters
Indigo matters because it connects agriculture, craft, chemistry, trade, and culture. A small green leaf becomes a blue pigment. That pigment becomes a vat. The vat becomes a dyed yarn or printed cloth. The cloth becomes a garment, a household textile, or a cultural object.
Every stage requires knowledge. The farmer must grow the plant. The extractor must know how to ferment and oxidize the leaves. The dyer must know how to prepare and maintain the vat. The printer must know the right paste consistency. The washer must know how to finish the cloth. The user finally sees only the blue colour, but behind that blue lies a chain of skilled work.
Traditional indigo is therefore not just a dyeing method. It is a complete knowledge system.
Conclusion
The traditional way of extracting and printing with indigo shows the depth of textile wisdom developed by artisans over generations. The process begins with leaves and water, moves through fermentation, oxidation, reduction, printing, drying, washing, and finishing, and finally produces one of the most loved colours in textile history.
Indigo teaches us that colour is not always immediate. Sometimes colour has to be prepared, transformed, hidden, released, and fixed. The blue that finally appears on cloth is the result of patience, observation, and careful control.
In this sense, indigo is more than a pigment. It is a story of transformation — from plant to paste, from vat to fibre, and from invisible chemistry to visible blue.
Related Reading on Natural Dyes, Vat Dyeing and Textile Printing
This article is intended for educational and informational purposes. Traditional indigo extraction, vat preparation, dyeing, printing, and after-treatment practices vary across regions, communities, materials, water quality, climate, and workshop methods. Chemical names and process descriptions have been presented in simplified form for textile understanding.
Where chemicals such as caustic soda, hydrosulphite, lime, iron salts, or other alkaline and reducing agents are used, proper safety precautions, ventilation, protective equipment, disposal practices, and local regulations should be followed. Readers should not treat this article as a substitute for hands-on training under an experienced dyer or for formal chemical safety guidance.
Is Indigo Natural or Synthetic? How Was Indigo Produced?
The answer to the first part of the question is simple: both. Indigo began its textile journey as a natural dye obtained from plants. Later, with the development of modern chemistry, the same blue colouring substance began to be manufactured synthetically.
Today, most of the indigo used in the textile industry, especially in denim, is synthetic. But historically and culturally, indigo is deeply associated with natural dyeing traditions of India, China and many other parts of the world.
Indigo belongs to the category of water-insoluble dyes. More specifically, it is a vat dye. This means that indigo, in its blue form, does not dissolve in water and cannot be applied to fabric directly like many other dyes. It has to be chemically converted into a soluble form before dyeing, and then converted back into the blue insoluble form on the fibre.
Indigo is one of the oldest dyes known to human civilization. It is believed to have been used for dyeing in India and China from very early times, possibly as far back as 2000 BC. The name “indigo” itself is connected with India. The Greeks and Romans referred to it as a blue dye coming from India, often described as “Indian blue.”
Originally, indigo was obtained from plants, especially from species such as Indigofera tinctoria. The leaves of the plant contained the precursor of the dye, but not the ready-made blue dye in a simple usable form. The blue colour had to be developed through fermentation, reduction and oxidation.
This is what makes indigo so fascinating. It is not merely a colouring matter extracted like juice from a plant. It is a dye that requires chemical transformation before it becomes useful.
Chemical Structure of Indigo
The main colouring compound in indigo is called indigotin. Its molecular formula is:
\[
C_{16}H_{10}N_2O_2
\]
The structure of indigo consists of two indole-like units joined together through a central double bond. It also contains two carbonyl groups \((C=O)\) and two nitrogen atoms. A simplified way to understand the molecule is:
The indigo molecule is highly conjugated. This means that electrons are spread over a large part of the molecule. This extended conjugation is responsible for the absorption of visible light and the characteristic deep blue colour of indigo.
Visual 1: Chemical structure of indigo, \(C_{16}H_{10}N_2O_2\).
This structure also explains why indigo is stable and water-insoluble. For dyeing, the molecule has to be temporarily converted into another form.
How Natural Indigo Was Produced
Natural indigo was traditionally obtained from the leaves and stems of indigo plants. The harvested plant material was placed in a vat filled with water. In older traditional processes, urine or other alkaline fermenting materials could also be used. Fermentation was then allowed to take place.
Inside the plant, the main precursor of indigo is indican, a colourless glucoside. During fermentation, indican breaks down into indoxyl and glucose.
This step is important because the plant does not directly give a strong blue dye. It first gives indoxyl, which is the immediate precursor of indigo. When the fermented liquid is stirred or beaten with poles, oxygen from the air enters the liquid. This oxygen oxidises indoxyl into indigo.
As indigo is insoluble in water, the blue particles begin to separate out and settle at the bottom of the vat. The liquid above is drained off, and the remaining blue sludge or mash is collected. This mash is then dried in the open air and sold in the form of pressed cakes, lumps or powder.
This traditional method explains why indigo production was both an agricultural activity and a chemical process. The farmer grew the plant, but the dyer or processor had to understand fermentation, aeration, settling and drying.
Visual 2: Natural indigo production from leaves to indigo cake or powder.
Indigo as a Vat Dye
Indigo is insoluble in its blue form. Therefore, to dye fabric with indigo, it must first be reduced into a soluble form called leuco-indigo. This reduced form is pale yellowish or greenish and can dissolve in an alkaline dye bath.
In this reduced form, indigo can enter or deposit onto the fibre. When the yarn or fabric is removed from the dye bath and exposed to air, oxygen converts leuco-indigo back into blue indigo.
This is the magical moment in indigo dyeing. The material may come out of the vat looking yellowish-green, but slowly turns blue as it reacts with oxygen in the air.
Practical textile point: This conversion from insoluble blue indigo to soluble leuco-indigo, and then back to insoluble blue indigo, is the heart of vat dyeing.
Visual 3: Indigo vat dyeing cycle: reduction, dyeing and oxidation.
Why Stirring Was Important
In traditional indigo production, the fermented mass was stirred or beaten with poles. This was not merely a mechanical operation. It had a chemical purpose.
During fermentation, the precursor compounds were converted into reduced or reactive forms. When the liquid was stirred, air entered the vat. The oxygen in the air converted indoxyl into indigo. Since indigo is insoluble, it appeared as blue particles and settled at the bottom.
\[
\text{Fermentation develops the precursor}
\]
\[
\text{Stirring introduces oxygen}
\]
\[
\text{Oxygen converts the precursor into blue indigo}
\]
\[
\text{Insoluble indigo settles at the bottom}
\]
This is why the process required both patience and skill. Too little fermentation, too much fermentation, insufficient aeration or poor settling could all affect the quality of the final dye.
From Natural Indigo to Synthetic Indigo
Thus, indigo began as a natural dye. For centuries, India was one of the important sources of natural indigo. Indigo was exported as a valuable dye material, and the term “Indian blue” became associated with it.
However, in the nineteenth century, European chemists began studying the structure and synthesis of indigo. Adolf von Baeyer made major contributions to the chemistry of indigo and succeeded in synthesising it in the laboratory. Later, in 1897, BASF began industrial-scale production of synthetic indigo.
This changed the dye industry completely. Synthetic indigo gave manufacturers a more consistent, predictable and scalable source of blue dye. Natural indigo depended on crop quality, climate, fermentation conditions and extraction skill. Synthetic indigo could be produced in large quantities with more uniform strength and shade.
Over time, synthetic indigo almost completely replaced natural indigo in large-scale textile production.
Natural Indigo vs Synthetic Indigo
Point
Natural Indigo
Synthetic Indigo
Source
Plant-based, mainly from indigo-bearing plants such as Indigofera tinctoria.
Manufactured chemically.
Main colouring compound
Indigotin.
Indigotin.
Molecular formula
\(C_{16}H_{10}N_2O_2\)
\(C_{16}H_{10}N_2O_2\)
Consistency
May vary from batch to batch.
More uniform and predictable.
Scale
Suitable for craft, heritage and natural dyeing.
Suitable for industrial denim production.
Process control
Depends on fermentation and extraction.
Depends on chemical manufacturing controls.
Present use
Niche use in natural dyeing, handcraft and sustainable fashion.
Dominant in denim and industrial textile dyeing.
The important point is that the main blue molecule is the same: indigotin. The difference lies mainly in the source, impurities, production method, consistency and environmental profile.
Indigo and Denim
Today, indigo is most strongly associated with denim. Cotton warp yarns are dyed with indigo, while the weft often remains undyed or lightly coloured. In denim dyeing, yarns are repeatedly dipped into the reduced indigo bath and then exposed to air for oxidation.
This repeated dipping and oxidation builds up the blue shade gradually. One interesting property of indigo dyeing is that the dye often remains more concentrated near the surface of the yarn rather than penetrating fully into the core. This is one reason denim fades beautifully with wear.
As the outer surface of the yarn is abraded, some of the indigo is removed, revealing lighter areas. This gives denim its characteristic worn, faded and aged appearance. So, in denim, fading is not always a defect. It is often part of the desired aesthetic.
A Small Correction to Understand the Old Process Better
In older descriptions, it is sometimes said that hydrogen was created by microorganisms and acted as a reducing agent. This is a simplified way of explaining the process. More accurately, fermentation creates reducing conditions in the vat. These reducing conditions help convert dye precursors into forms that can later be oxidised into indigo.
Similarly, when the liquid is stirred, the aim is to introduce oxygen. Oxygen converts the soluble or reduced precursor into insoluble blue indigo. The blue particles then settle at the bottom.
\[
\text{Reduction during fermentation}
\]
\[
\text{Oxidation during beating or aeration}
\]
This reduction-oxidation cycle is also central to indigo dyeing on fabric.
Conclusion
Indigo is both natural and synthetic. Historically, it was obtained from plants and processed through fermentation, aeration, settling and drying. Later, chemists discovered how to produce the same blue colouring substance synthetically. With industrial production by BASF in the late nineteenth century, synthetic indigo gradually replaced natural indigo in most commercial textile applications.
The beauty of indigo lies in its chemistry. It is a water-insoluble vat dye. It must first be reduced to a soluble leuco form, then applied to the fibre, and finally oxidised back to the blue insoluble form.
This is why indigo is not just a dye. It is a story of plants, fermentation, chemistry, trade, denim and textile technology.
Related Reading on Indigo, Natural Dyes and Dyeing
This article is intended for educational and general textile knowledge purposes only. The chemical reactions shown are simplified to explain the main principles of natural indigo formation and vat dyeing. Actual indigo extraction, dye reduction, denim dyeing, effluent treatment and chemical handling require proper technical knowledge, safety precautions, process control and laboratory or mill-level validation.
a. Take 200 gms of Myrobalan powder for 1 kg of fabric
b. Make a smooth paste with water, without any lumps
c. Add water till it becomes 5 liters.
d. Mix well
e. Soak the fabric in this
f. Work the fabric in this solution at room temperature for 15 to 20 minutes.
g. Squeeze the material and dry it in shade.
h. When dried, remove the unfixed material by striking it against wall.
2. Preparation of Thickening Agent
Using Tamarind Seed Powder
a. Add 100 gms of Tamarind seed powder in 1 liter of boiling wter.Sprinkle the powder in the boiling water stirring to avoid lumps.
b. Cook and mix till a fine paste is ready, cool it and filter the contents.
c. Remember that this paste is stable only for 2 to 3 days.
Or
Take Bhagvathi gum, add 30 to 50 gms of powder for 1 liter of water. It is also soluble in cold water.
This paste has better stability
Avoid Gum Arabic.
3. Mordanting the Solution with Mineral Salts
Take the mineral salts according to the following formula:
x parts of mineral salts 15 to 20% boiling water 70% thickening agent to make it 100%.
The following are the general guidelines for getting the dark shades.
Alum= 10%, available by the name of Fitkari Potassium Dichromate= 5%, available as Lal Kashish Copper Sulphate= 10%, available by the name of mor Thuth Ferrous Sulphate= 1 to 5%, available by the name of Hira Kashish Iron Solution = 50%
Iron solution is made by the following procedure:
a. Take 2 kg of Iron Pieces, 1 to 1.5 kg of Jaggery and add 20 liters of water.
b. Keep in a plastic container for 3-4 weeks
Tin Chloride= 0.5 to 1.0 %
The Procedure for making the paste is:
a. Ground the mineral salt into powder form. b. Add water and boil. c. When completely dissolved, add the thickening agent.
The paste is ready for the printing process
4. Printing
Now Print the fabric using blocks. Dry and wash as follows:
5. Washing
When washing in river keep the printed portion face down so that it touches water. Wash for about 5 to 10 minutes, printed portion is not touched. Care should be taken that printed portion should not touch the unprinted portion.
After washing, dry in flat on the ground. Dont hang. Now the fabric is ready for developing.
6. Developing of Color
Fabric is developed using traditional material. For yellow ranges Pomegranate rind ( Anar ka Chilka) or Forest Yellow (Amba Haldi) 50% or Moduga flowers ( Desuda phool) are taken. For Pinks to reds maroons Alizarin(0.5% with 10-20% Dhavdi flowers added to dye bath), Mnajistha(25-50%) is taken, for grey ranges: Rathanjoth(30% to 50%), Ferrous Sulphate is taken, for brown range: catechu ( Katha) and its componets are taken.
Powder the dye and mix and boil with water for 3-4 boils. Filter it. Make a dye bath with material to Liquor ratio of 1:20 at 50 deg C. Add the solution in it. Enter the fabric ( already mordanted ) in it. Work well and raise the temperature to boil. Dye for 30-40 minutes. Wash and soap. Dry in shade.
In traditional methods in India, printing is essentially carried in three steps:
1. Preparation of the Cloth 2. Mordanting 3. Dyeing
1. First of all the cloth is prepared by applying tannin.
2. A thickened mordant is printed on this tannin treated cloth in the desired pattern.
3. The cloth is then dyed so that dyestuff attaches itself to those parts of the cloth to which mordant has been applied.
Thus the various processes are:
a. Tanning of fabric b. printing of mordant c. fixing of the modant d. washing out the excess of fixing agent e. dyeing f. washing and soaping.
Harda or Myrobalan is used in India as a tanning agent for dyeing and printing with natural colours.
It is applied on scoured cotton fabric in cold ( 10-40 gpl) using conventional method of tub dip wherein the Harda powder is replenished with each piece added to the bath.
After drying various metallic salts such as alum or ferrous sulphate are printed on the fabric either separately or in mixtures.
It is then subsequently dyed with madder root ( Manjith), pometranate rind, kusum flowers and other vegetable dyes.
