Indigo 

Indigo is a natural dye that has been used since ancient times to obtain beautiful shades of blue ranging from sky blue to dark blue, almost black. However, many people hesitate to use indigo for dyeing, as it is a difficult dye to work with, mainly because it is not soluble in water.

To meet this challenge, the main colouring component has been extracted from the leaves of the plant Indigofera tinctoria using biological and ecological methods. The basic substance of indigo blue is indigotine, a dark blue crystalline powder that does not dissolve in water or alcohol. To make it soluble, it is necessary to use an alkaline bath in which the oxygen is removed through a fermentation process.

Natural indigo offers significant advantages, as it produces a more intense blue and, as it is not soluble in water, allows fabrics to be washed repeatedly without loss of colour. Furthermore, no mordant is required for dyeing. This dye is also sustainable: after extraction of the pigment, the plant residue can be composted and used as fertiliser, while the water used in the process can be reused for irrigation.