cocoon

The oval casing of filament silk, or brin, spun by the silkmoth larvae or caterpillar, the silkworm, to protect itself when it changes into a chrysalis. The silkworm extrudes through the silk glands in its head a viscose fluid building up round itself layer upon layer crossing the filaments in a figure of eight. Colour of cocoons, which is contained in the sericin is removed in the degumming, range from white to yellow, golden yellow and brown.  The cocoon grading system in France has become the standard for Europe and India.  They are sorted into nine different grades:

1. Good cocoons, Perfect for mechanical reeling
2. Pointed cocoons, No good for mechanical reeling
3. Cocalons, Larger than normal
4. Duppions, Double cocoons
5. Soufflon, Loose or transparent
6. Perforated, Pierced or broken
7. Good choquettes, Containing dead chrysalis
8. Bad choquettes, Rotten cocoons
9. Calcinated, Containing petrified chrysalis