The oldest indigo-dyed fabric commonly used in modern jeans was first discovered in Peru around 6,000 years ago. Researchers at George Washington University said that the source of the blue pigment was unknown until this study.
The findings are published in Science Advances and are based on the analysis of blue pigment in a 6,000-year-old piece of cotton fabric found at an archaeological site in Huaca Prieta, on the north coast of Peru.
This recent study, which used highly sensitive equipment known as high-performance liquid chromatography to determine it was a plant-based form of indigo.
The findings point to the sophisticated textile technology ancient Andean people developed, said the study led by author Jeffrey Splitstoser, Assistant Research Professor at George Washington University.
“The cotton used in Huaca Prieta fabrics, Gossypium barbadense, is the same species grown today known as Egyptian cotton,” Splitstoser said.
“And that’s not the only cotton connection we made in this excavation — we may well not have had blue jeans if it weren’t for the ancient South Americans,” Splitstoser noted.
The discovery marks the earliest use of indigo as a dye, a technically-challenging colour to produce.
“Some of the world’s most significant technological achievements were developed first in the New World,” Splitstoser said.
“Many people, however, remain mostly unaware of the important technological contributions made by Native Americans, perhaps because so many of these technologies were replaced by European systems during the conquest. However, the fine fibres and sophisticated dyeing, spinning and weaving practices developed by ancient South Americans were quickly co-opted by Europeans,” Splitstoser explained.
The development of indigo dye was critical for future trends in fashion, fabrics and textile arts, he said.
(With agency inputs)