== History accurate ? == 
 Hi, i found a source in german from 1872 stating the invention of glass fibers by Jules de Brunfaut (French) in 1849 and their use in textiles and filters (Emanuel Herrmann: Miniaturbilder aus dem Gebiete der Wirthschaft. Nebert, 1872. p. 23–29.) And another source (by Saint Gobain) describes the invention (german patent 539738) of glass fiber non-wovens by Friedrich Rosengarth (German) in 1930, which was subsequently bought by the author. What to make of it? Cheers,