SHANGHAI, Aug. 11 -- A DYEING technique dating back thousands of years has been embraced by a group of local postgraduates.

They are trying to streamline the environment-friendly process and will go public with their end product during the World Expo 2010 Shanghai.

The student group at Donghua University last month conducted a social-practice program to explore living and cultural traditions of the black-clad Zhuang ethnic group, a minority community living in remote mountain areas of southeast Guangxi Zhuang Autonomous Region.

The ethnic minority, which has a population of just 51,800, was named after their special worship of black clothes.

An isolated living environment prevented the Zhuang people from presenting their cultural traditions to the outside world, said Chen Liyan, one of the Donghua students.

During the three-week visit, Donghua students came to discover that the ethnic group used indigo for dyeing garments.

Cloth dyed with the natural plant sends out a delicate fragrance, has a mosquito-repelling effect and provides a healing effect.

"It is really a rare magic craft, which lives up to the modern e-friendly concept," said Yang Biling, a doctoral student at Donghua's garment dyeing department, another group member. "It will be of great value to the modern dyeing industry."

However, she said that the Zhuang people's traditional craft does have drawbacks, such as low productivity. For instance, it takes about 25 days to dye a single roll of cloth.

Donghua students have designed an improvement scheme, trying to shorten the required dyeing time as well as reducing the cloth weight to make it lighter and softer.

The Shanghai World Expo Coordination Bureau has agreed to help them with publicity.