Various kinds of blue calicos and a bag made of the cloth. [Photo/zjgonline.com.cn]

Ren Lu, who owns a studio at Qinglong village in Tangqiao town, Zhangjiagang, is an inheritor of the blue calico crafting technique that dates back to over 1,000 years.

The first step in making the blue and white cloth is the drawing of patterns, said Ren. Traditional patterns, which are usually symmetrical, are mostly about animals, flowers, and figures in ancient Chinese mythology. To ensure accuracy and avoid possible dyeing problems, the patterns are sometimes only finalized after 20 to 30 revisions, according to Ren.

A pattern is carved on thick Kraft paper. [Photo/zjgonline.com.cn]

Next, the final draft of the patterns is carved on thick Kraft paper, which will be later placed on a piece of white cotton cloth, with the cutouts filled with dye-resistant paste. After the paste is completely dried in the shade, the cloth can be soaked in a vat of dye. The dyeing process may need to be repeated many times before the desired color is produced.

Depending on the size of the cloth and the complexity of the patterns, the whole process can take a few days to several months, said Ren.

Ren had in 2021 attended a blue calico making technique training session organized by Nantong University to improve his skills. He has created many works themed on Zhangjiagang and held a series of activities to encourage teenagers to learn about the intangible cultural heritage.