WCO Explanatory Notes reproduced for reference. © World Customs Organization. Verify against official WCO publication.
50.05 - Yarn spun from silk waste, not put up for retail sale. This headin covers single yams produced by spinning the noil or other silk waste of heading 50.0 ;it also covers multiple (folded) yarns produced from these single yarns. b) The are, however, excluded if put up for retail sale heading 50.06 or if within the definition of twine, cor&e, etc. (heading 56.07) (see Parts (I) (B) and (3) o the G e n d Explanatory Note to Section XI). (A) Yarn spun from silk waste other than noil silk. Yarn spun fiom silk waste other than noil silk, unlike the silk yarn o,f the preceding heading, is formed of discontinuous fibres. These fibres, which may be u to 20 crn long, lie parallel in the yarn, giving it a smooth, silky and fairly glossy sur ace; these latter characteristics distinguish it from yam spun from noil silk. F (B) Yarn spun from noil silk. Noil silk yarns are of much poorer quality than other silk waste yarns; they are composed of fibres of varying lengths, usually less than 5 cm; since these fibres have simply been carded but not combed, they are usually still somewhat tangled and form small knots at intervals. Noil silk am according1 lacks the strength and regularity of yarn spun from o.ther silk waste and as a rather dul surface. r The heading includes yam which has been processed as described in Part (I) (B) (1) of the General Explanatory Note to Section XI. The heading excludes imitation catgut of silk, of heading 56.04.
Silk GENERAL The General Explanatory Note to Section XI should be taken into account in reading the Explanatory Notes to this Chapter. P For the urposes of this Cha ter the term " silk covers not only the fibrous matter secreted by the Bom%yx mori mulberry eeding silk-worm), but also the products of the secretion of similar insects e.g., Bom yx textor known as wild silk. Among the wild varieties, so named because the pro ucmg worm has on y very rarely been domesticated, the most important is tussah silk obta~nedfiom a silk-wonn that feeds on oak. Spider silk and marine or byssus silk (the filaments by which certain shellfish of the Pinna family cling to rocks) are also classified in this Chapter. Generally speaking, this at its vmous stages of silk-worm gut. " ter covers silk, including mixed textile materials classified as silk, from the raw material to the woven fabric. It also includes