KANO, Nigeria - The technique used by a group of northern Nigerian craftsman to dye cotton sheets indigo has survived for more than 500 years, but the risks of extinction have never been higher.
At the dye pits in Kano, Nigeria's second city, a solution made up of natural indigo, ash and potash is brewed for at least a month in a shaft shaped like a well dug six-feet deep.
The 125 "Kofar Mata" pits were constructed in a walled compound in central Kano in 1498 and assigned to individual families whose descendants are said to still control the trade.
"Clinging to our local technique has been the secret to our survival," said 38-year-old Yusuf Sa'id.
"Sometimes it pays to be conservative."
A commitment to a centuries-old practice may have helped dye pit operators withstand developments that have devastated Kano's textile industry.
Despite being Africa's top oil producer, Nigeria has failed to provide a reliable flow of electricity to its people, forcing industries to spend heavily on generators.
The high cost of operating a business, combined with the influx of cheap foreign fabrics, especially from China, have forced the closure of all of Kano's 20 textile factories over the last two decades, said Ali Madugu, deputy head of Nigeria's main manufacturers union.
Manufacturing in general has all but collapsed across the city of some five million people.
The dye pits are however cheap to run, requiring no electricity, and still have loyal customers seeking the unique product.
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