Drawing silk: The first step is drawing silk. The cocoons have to be sorted out first and the dirty and abnormal-shaped cocoons have to be boiled in water for about 15 minutes until the cocoons change to green color and are soaked with water. Then a stick is used to stir the cocoons and twist the fiber threads of the raw silk into strands. Normally, 25-30 threads make one strand. [Photo provided to chinadaily.com.cn]