Photo taken on March 9, 2021 shows a piece of dyeing work at a research institute in Lanzhou Jiaotong University, northwest China's Gansu Province. The dyes used in this ancient printing and dyeing technique are all natural. Such technique has been listed as a provincial-level intangible cultural heritage.

A staff member of a research institute in Lanzhou Jiaotong University designs a dyeing pattern at the institute in Lanzhou, northwest China's Gansu Province, March 9, 2021. The dyes used in this ancient printing and dyeing technique are all natural. Such technique has been listed as a provincial-level intangible cultural heritage.

Photo taken on March 9, 2021 shows a piece of dyeing work at a research institute in Lanzhou Jiaotong University, northwest China's Gansu Province. The dyes used in this ancient printing and dyeing technique are all natural. Such technique has been listed as a provincial-level intangible cultural heritage.

Guan Lansheng (1st R), director of a research institute in Lanzhou Jiaotong University, stirs the dye vat at the institute in Lanzhou, northwest China's Gansu Province, March 9, 2021. The dyes used in this ancient printing and dyeing technique are all natural. Such technique has been listed as a provincial-level intangible cultural heritage.

Photo taken on March 9, 2021 shows raw materials for dyeing at a research institute in Lanzhou Jiaotong University, northwest China's Gansu Province. The dyes used in this ancient printing and dyeing technique are all natural. Such technique has been listed as a provincial-level intangible cultural heritage.

A staff member of a research institute in Lanzhou Jiaotong University makes dyestuff with natural flowers in Lanzhou, northwest China's Gansu Province, March 9, 2021. The dyes used in this ancient printing and dyeing technique are all natural. Such technique has been listed as a provincial-level intangible cultural heritage.

Photo taken on March 9, 2021 shows a cheongsam with dyeing technique at a research institute in Lanzhou Jiaotong University, northwest China's Gansu Province. The dyes used in this ancient printing and dyeing technique are all natural. Such technique has been listed as a provincial-level intangible cultural heritage.

Photo taken on March 9, 2021 shows a piece of dyeing work at a research institute in Lanzhou Jiaotong University, northwest China's Gansu Province. The dyes used in this ancient printing and dyeing technique are all natural. Such technique has been listed as a provincial-level intangible cultural heritage.