Cloth has been discovered in Peru that has provided the earliest evidence of the use of indigo dye. The fabric found is about 6,200 years old, which makes it older than the former oldest known sample of indigo dye, which came from Egypt.
The fabrics were first found in 2007 at the ancient ceremonial hill known as Huaca Prieta, located in Northern Peru. Specialists think that this site was a temple where people left a variety of offerings, such as textiles, as part of a ritual.
The cloth was initially so dirty that it appeared colorless. After cautiously washing the fabric and using a technique known as high-performance liquid chromatography, experts isolated portions of a dye.
Five out of the eight samples that the researchers put through tests were discovered to have traces of indigo. The other samples might have decayed over time.
Most indigo dye comes from the organic compound known as indigoid. This can be found in plants such as Indigofera. Specialists stated that the ancient Peruvians had likely obtained indigo dye from this specific plant, whilst the Egyptians got this coloring from sea snails. Indigo can be quite complicated to make, so this discovery suggests a high level of skill and knowledge present in ancient Peru’s textile industry.
While several dyes can be created by just boiling flowers in water to pull out the color, making indigo dye requires leaves that have been fermented. After they are fermented, the leaves must be aerated in a container so that a solid compound separates from the mixture and sinks to the bottom. Reconstituting the mixture, which could be stored and dried, requires an alkaline substance such as urine, which can also create white indigo. When the yarns are dipped into the white indigo they will turn yellow, then green, and ultimately blue.