Silk is insect fibre. It comes from the silkworm cocoon that the silkworm spins around itself to form its cocoon. A single filament from a cocoon can be as long as 1600 metres. It is considered an animal fibre because it has a protein structure. Just like other animal fibres silk does not conduct heat, and acts as an excellent insulator to keep our bodies warm in the cold weather and cool in the hot weather.
Silk has lustre, drape and strength. There are three grades of silk, each a product of the three different stages of silk processing. The unwound filament makes the finest quality silk, and is referred to as reeled silk. It is satiny smooth and pure white. Remaining silk from the reeling process becomes the raw material for carded or combed, spun silk yarn. The short fibres left behind after the carding or combing process are used to make noil yarn, a richly textured nubbly silk.