Indigo dye
Indigo is one of the oldest known natural dye used in ancient times to get natural blue extracted from Indigofera tinctoria plant leaves. Indian subcontinent was famous for its cultivation and used in dyeing traditional block printed clothes. It was one of the early known natural dye used in cold form by fermenting the indigo leaves or powder extracted from leaves through as certain process.
In today's time natural indigo is used by very few dyers in organic form. To prepare a vat or dye pot any plastic drum or underground cemented tank is used. Size of the indigo vat depends upon the use and demand. Traditionally a pitcher is used to prepare a indigo vat. There are 3 variants of Indigo color is available in the market today.
Maheshwari handloom cotton tie dyed with organic natural indigo
Organic Natural Indigo
First we talk about the indigo used to ferment using organic process with natural ingredients. It is very important to use natural ingredients if any dyer is using natural indigo otherwise it is of no use to make a natural indigo vat. The natural ingredients used in preparing organic natural indigo vat are:
1. Water
2. Natural indigo cake or powder
Indigo cake
3. Cassia tora seeds (It attracts bacteria to fasten the fermenting process and extracting the color from indigo powder)
Cassia tora seeds
4. Lime (To make water alkaline and maintaining the ph value of the vat)
Lime in crystal form
5. Jaggery or sugar (A natural source of fructose works as a reducing agent)
Jaggery crystal
By mixing all the natural and organic ingredients in water with indigo powder a natural indigo vat get prepared.
Organic natural indigo vat by EcoFab
Using all these natural and organic ingredients in preparing organic natural indigo vat requires 12 to 24 hours in activation. It also depends upon the weather and use of ingredients in proportion.
Natural Indigo with synthetic process
Natural indigo is prepared using natural indigo with synthetic chemical ingredients. Ingredients used in preparing natural chemical indigo vat are:
1. Natural indigo cake or powder
2. Lime
3. Caustic soda (Heavy chemical with toxic property)
4. Sodium hydrosulphite (Heavy chemical with toxic property)
If some dyer is using synthetic chemical ingredients as a reducing agent in preparing natural indigo then it is of no use because the natural herbal properties of indigo got nullified while using heavy synthetic chemical based reducing agents in preparing the vat.
Why people use synthetic chemical ingredients in natural indigo?
1. It get activated within 30 minutes of preparing vat
2. Easy to maintain using chemical ingredients
3. Non- availability of cassia tora seeds or unaware about it
4. Sometimes no access to knowledge of preparing organic indigo vat
Synthetic Indigo
Most of the indigo products available in the market are flooded with synthetic chemical indigo dyed products marketed as natural indigo dyed products. After introduction of synthetic version of indigo in the market every hand block printing cluster is using synthetic (chemical) indigo to dye the fabrics.
Synthetic indigo vat get prepared using synthetic chemical ingredients only.
Ingredients used in preparing synthetic chemical indigo vat are:
1. Synthetic/chemical Indigo known as German indigo
2. Lime
3. Caustic soda (Heavy chemical with toxic property)
4. Sodium hydrosulphite (Heavy chemical with toxic property)
Why hand block printers or dyers use chemical indigo?
1. Pricing of synthetic chemical indigo is 2 to 3 times cheaper than natural indigo
2. Maintenance of chemical indigo vat is easy
3. Quick demand
4. Lack of knowledge about preparing natural organic indigo vat
Now the million dollar question is how to identify the difference in between synthetic chemical & natural indigo?
It is not easy to identify the difference of shades in between organic natural, natural chemical and chemical indigo dyed fabrics initially. It all depends upon the level of honesty and transparency of block printer, dyer or marketing company to mention it.
