Indigo
We use Tinctora Indigo, grown locally in Rajasthan. Scientifically named Indigofera Tinctoria, which is known in the dyeing trade as ‘True Indigo’. This legume species, originally a source of indigo dye, has been cultivated globally for centuries, with its native habitat now unknown. True Indigo typically grows as a shrub between one to two meters tall and can be annual, biennial, or perennial, depending on the climate. It features light green pinnate leaves and pink or violet flowers.
The dye is extracted from the plant's leaves through a process of soaking and fermentation, which converts the glycoside indican into the blue dye indigotin. Unlike other dyes, indigo forms a physical bond with fabric rather than a chemical one, requiring a reduced state for bonding, as it is insoluble in water.
When applied to fabric, indigo creates layered bonds that enhance its resistance to sunlight, although it may fade with abrasion. Indigo dye is characterized by its distinctive blue color and is classified as an organic compound.
Madder
Rubia tinctorum, commonly known as madder, is a perennial plant in the Rubiaceae family. It has been used since ancient times to produce a red dye for various materials, including leather, wool, cotton, and silk.
The dye is obtained from the plant's roots, which are harvested after two years. The outer layer of the root produces a common dye, while the inner layer yields a refined version. A mordant, typically alum, is used to fix the dye to fabrics. Additionally, madder can be fermented for dyeing purposes.The roots contain ruberthyrin, which can be transformed into sugar, alizarin, and purpurin through drying, fermentation, or acid treatment.
Alizarin was first isolated in 1826 by chemist Pierre Jean Robiquet. While purpurin is usually colorless, it appears red in alkaline solutions. When mixed with clay and treated with alum and ammonia, it creates a vibrant red colorant known as madder lake.
Lac
Lac is a red resin produced by lac insects, primarily Kerria lacca.
To cultivate lac, a farmer attaches a stick containing hatching eggs to a tree, allowing the insects to infest the branches and secrete the resin. The branches, now coated with lac, are harvested as sticklac. If dye is being produced, the insects are left in the sticklac since the dye color comes from them. The harvested sticklac is then crushed, sieved to remove impurities, and washed to eliminate insect parts.
Lac dye has been used since ancient times in India for wood finishing, cosmetics, and dyeing wool and silk, and it is also a traditional dye for leather goods in China.
Pomegranate
The pomegranate (Punica granatum) is a deciduous shrub or small tree that grows 5 to 10 meters tall. Its spherical fruit, up to 12 cm in diameter, has tough skin and contains many seeds surrounded by ruby-red pulp.
The pulp can be used for juice and grenadine syrup, while the seeds can be ground into a spice called anardana. The rind is also utilized as a dye, with one tree producing about 1 kilogram of dried rind annually.
Himalayan Rhubarb
Rheum nobile, also known as Noble rhubarb or Sikkim rhubarb, is a large herbaceous plant found in the Himalayas, ranging from northeastern Afghanistan to Myanmar at altitudes of 4000–4800 meters.
This remarkable rhubarb species can grow 1–2 meters tall, making it the tallest plant in its environment, visible from a mile away. Its leaves can reach up to 1 meter in diameter and are used for lining and protecting fruit in baskets. Additionally, a bright yellow dye can be extracted from its root.
Catchu
Catchu is an extract from acacia trees, particularly from the species Senegalia catechu. It is obtained by boiling the wood in water and evaporating the liquid. This extract is rich in natural vegetable tannins, which provide its astringent properties and make it useful for tanning animal hides.
Known as Cutch, it serves as a brown dye for tanning and dyeing purposes, as well as for preserving fishing nets and sails. Cutch can dye wool, silk, and cotton a yellowish-brown, producing grey-browns with an iron mordant and olive-browns with a copper mordant.
Marigold
Calendula officinalis, commonly known as pot marigold, likely originated in southern Europe, but its exact origin is unclear due to its long history of cultivation. It is now found in various warm temperate regions, including parts of northern Europe.
Historically, the flowers have been used in ancient Greek, Roman, Middle Eastern, and Indian cultures for medicinal purposes and as a dye for fabrics, foods, and cosmetics, with many of these uses still relevant today.
To note, 1 kg of marigold petals dries to 165 grams, which is sufficient to dye only about one dress.