Indigo - Añil, Some traces of the blue pigment were found in pre-Hispanic remains. There is evidence that it has been used in Mexico and Central America since ancient times. Upon the arrival of the Spanish, the production and export of this highly valued colourant in Europe increased considerably.
Along with India, the New World countries were the main producers of indigo, which at the same time undermined the production of "Pastel Blue", a pigment created in the south of France.
In the 19th century, the natural indigo molecule was identified. Its chemical substitute allowed industrialists to manufacture a low-cost and more profitable blue dye while leaving out natural indigo.
In the natural indigo producing countries, production is now very low. It is a rare, valuable and expensive product because it is highly dependent on weather conditions. The plant is harvested once a year and the manufacturing process is long and very precise.
Fabrication process: The "indigo blue" dye is found as a fermented paste. To obtain this dye, a manufacturing process known since pre-Hispanic times must be followed.
1. The leaves and tender branches of the Indigofera shrub, also known locally as the Xiquilite (or Xiuhquílitl, “blue grass” in Nahuatl), are harvested after the rains in September and October.
2. Both elements are crushed, deposited in a container and kept at the bottom with stones. The container is filled with water and left that way for at least 12 hours. Then the juice dissolves in the water.
3. Then the mixture is shaken and aerated for several days so that oxygen can enter. This causes a fermentation that allows the blue dye to be soluble; it is called Indigotine. The mixture is allowed to stand so that the blue sediment settles at the bottom of the container.
4. Then the colourant mixed with the water is filtered and dried in the sun to obtain a paste that can be used for dyeing. Manufacturing can take up to ten days.
Indigotine, which is insoluble, can be extracted directly from the used water. To dye, you have to mix with a reducer so that it is soluble and therefore will penetrate the fibres. In contact with the air, a new oxidation occurs that gives the pigment its final colour, restores its insoluble character and becomes very resistant to washing. Today, in Mexico, indigo is still cultivated and produced in some regions and communities of Michoacán (Huacana), Puebla (Hueyapan), Chiapas and Oaxaca (Santiago Niltepec). It is these towns that allow the artisans of Oaxaca to weave their blue wool threads.
Indigo - Añil
Añil the Mexican indigo is produced from Indigofera suffruticosa, commonly known as Guatemalan indigo, small-leaved indigo (Sierra Leone), West Indian indigo, wild indigo, and anil, is a flowering plant in the pea family, Fabaceae.
Añil is native to the subtropical and tropical Americas, including the southern United States, the Caribbean, Mexico, Central America, and South America as far south as northern Argentina. This species has been widely introduced to other parts of the world and today has a pantropical distribution. It is an erect branching shrub growing to 1 m (3.3 ft) tall with pinnate leaves, and is commonly found growing in dry, highly disturbed areas such as roadsides and fallow fields.
Anil is commonly used as a source for indigo dye, and if mixed with Palygorskite clays, can produce Maya blue, a pigment used by the Mesoamerican civilisations.
Botanical name: Indigofera suffruticosa Mill. (Añil)
Common names: Añil, Mexican indigo, azul añil, indigo
Primary dyestuff: Leaves
Key components: Indoxyl
Class of dye: Vat dye
Light and wash-fastness: High
Colour: All shades of blue. Green and black when itis mixed with other dyes.
Dye bath method: Indigo is a vat dye and unlike other natural dyes, it is not soluble in water, instead it is soluble in an alkaline environment from which the oxygen has been removed.
Recommended quantity of dye: I love the organic recipe from natural dye master Michel Garcia: the 1-2-3 vat.
1 part powdered natural indigo / añil
2 parts calcium hydroxide, also known as slaked lime, cal, calx
3 parts fructose crystals
First, you must decide what shade of blue you want to dye with your vat. That is to say, to light, medium, and dark indigo vats as a way to talk about the amount of indigo in each vat and how much and how dark a vat will dip. However, since indigo dyeing involves layering multiple dips on a piece to build up the colour, it’s possible to dye something a dark blue in a light indigo vat, but it will take more dips in the vat and more time to build up the colour. It is difficult to dye a light blue in a dark vat as the fiber is not in the vat long enough for the indigo to strongly attach and the light shade may streak, fade or wash out.
The amount of indigo in a vat is expressed as grams of indigo per liter of liquid in the vat, or gpL. Calculate the amount of liquid that your vat container can hold, leaving room for you to dip textiles into the vat without crowding or touching the sediment layer at the bottom of the vat. Once you know the amount of indigo you want to use in your vat, you can calculate the other ingredients based off of this gpL number.
Example, for a vat of about 15 to 20 litres 20 g powdered indigo 40 g calcium hydroxide (slaked lime) 60 g fructose
Swatch: