Elastane is the same as Spandex. Both are yarns that are knit/woven into fabrics, and contribute stretch and recovery properties to the fabric. Spandex is DuPontâs brand, elastane is the generic name.
In Latin 'Libra' are the symbol for the scales, hence the use of lb for weight (and lbs for the multiple),
1 Pound = 16 Ounces. Pound is a unit of mass in U.S customary, imperial and other different measurement systems including the historical ones (Romans called it libra and that's why it's abbreviated as lb and lbs today).