From Knitting for Olive:
Knitting for Olive Pure Silk is a soft, exclusive yarn of pure bourette silk (raw silk) produced from silk fibers collected from cocoons after the chrysalises are allowed to mature into moths and escape.
Silk has extensive heat-regulating qualities and can therefore be used in garments all year round. Silk can absorb up to 30% of its weight in moisture while still feeling dry against your skin, so it is especially suitable for summer wear. At the same time, silk, like wool, has insulating properties, retaining heat in cold weather.
The little butterfly on the label indicates that the chrysalids were allowed to evolve into butterflies, thereby allowing them to complete their life cycle.Patterns for Pure Silk