Since thousands of years ago, silk has been treasured as much as diamond and pearl. It is because silk has its unique aroma which no man made fiber can equal to. People in any part of the world can not enjoy a really rich living or a bright frame of mind without wearing silk. This means the silk is only silk. Mystery of silk and mysterious quality of silk come from the fact that it is a protein fiber produced by the living insect, namely, the silkworm. (omitted)