The provided illustrations delineate two distinct but connected processes: the natural biological life cycle of the silkworm moth and the subsequent linear stages involved in the commercial production of silk fabric.
Overall, the life cycle of the silkworm is a cyclical, four-stage natural phenomenon. In contrast, the manufacturing of silk is a five-step industrial process that interrupts the natural cycle by harvesting the cocoon to extract the raw material.
The biological cycle initiates when an adult moth deposits eggs on mulberry leaves, which serve as the primary food source. Following an incubation period of ten days, silkworm larvae emerge and feed voraciously on the leaves for a duration of four to six weeks. Subsequently, the larva encases itself by spinning a cocoon out of silk thread, a phase lasting between three and eight days. Under natural circumstances, after another 16 days, a mature moth would emerge from the cocoon to restart the cycle.
However, for silk cloth production, this cycle is intercepted at the cocoon stage. Selected cocoons are first boiled in water to prepare them for unwinding. Each cocoon yields a substantial length of thread, ranging from 300 to 900 meters. Once unwound, multiple threads are twisted together to create stronger yarn. Finally, this yarn is woven into material, which is subsequently immersed in dye to add color.