Garnetted stock is silk fiber recovered by mechanically pulling apart worn or waste silk textiles and fabrics, reducing them back to a fibrous state. Yarn waste, by contrast, is the off-cuts and broken filaments generated during spinning, throwing, or weaving operations. Both are classified under heading 5003, but their fiber length and quality differ, affecting their suitability for re-spinning.

Cocoons unsuitable for reeling — because the moth has emerged, the cocoon is double, or the filament is broken — are classified as silk waste (5003). Only cocoons from which a continuous filament can be mechanically reeled qualify as silkworm cocoons suitable for reeling (5001). The test is whether the continuous filament is intact and recoverable.