Japan prides itself on silk as a symbol of the beauty of textiles. But how many producers' passions are woven into the unique texture of silk produced by cocoons? We explore the story behind the birth of "Sanko," a silk brand committed to domestic production, from sericulture to silk reeling and weaving.
■Silk-raising techniques passed down from ancient times: at its peak, raw silk accounted for 70% of exports.
Did you know that from the Meiji period to the 1960s, raw silk (silk thread reeled from cocoons) was one of Japan's leading exports?
Sericulture techniques were introduced to Japan around 200 BC, believed to have been introduced from China along with rice cultivation. Silk-raising techniques, including sericulture, reeling, and twisting, have been independently developed and passed down and improved over time. During the Meiji period, mass production and export of raw silk became a national policy, earning enormous amounts of foreign currency. Raw silk was the fuel that propelled Japan toward modernization, and at its peak, Japanese raw silk was so highly regarded abroad that it accounted for 70% of exports. However, with the advent of synthetic fibers such as nylon in the 1960s, Japan's sericulture industry (sericulture and silk reeling) began to decline. Along with sericulture farmers and silk reeling factories, raw silk production also plummeted...

■ The Sankou Story: Passing on Japanese Silk to the Next Generation and Creating World-Class Silk Fabrics

Currently, domestically produced silk accounts for less than 1% of the total silk consumed in Japan. Against this backdrop, Sankou, a domestic silk brand, was born with the desire to produce silk entirely domestically, from sericulture to silk reeling and weaving. The Sanko Project began in 2005 with the goal of "passing on Japanese silk to the next generation and creating silk fabrics that the world can be proud of." Aiming to create silk with a refined luster and supple texture, the project, with the cooperation of researchers at the Sericulture Technology Research Institute, has been working tirelessly to improve silkworm breeds. It took over 20 years of crossbreeding with Japanese silkworm species to create the Sanko silkworms that produce thin, supple thread. ■Improved silkworm eggs are carefully raised by breeding companies and contract farmers. Silkworms grow by repeatedly molting and begin to spin cocoons after their fourth molt. The period up to their first molt is called the first instar, and they spin cocoons when they reach their fifth instar. Silkworms are delicate creatures that are susceptible to heat, cold, and disease, making them a labor-intensive process to raise. Until their third instar (their third molt), special care must be taken to prevent infection and regulate temperature. Sanko silkworms are raised and managed by a specialized company called Kogensha until they reach the third stage. After that, they are entrusted to silkworm farmers in Ina City, Nagano Prefecture, where the water and soil are good and high-quality mulberry trees can be harvested. High-quality cocoons are produced from Sanko silkworms that are raised with love and care.

Continued in the second part.