D. ; Hubinger, M. V. . Its pearl-white filament, above all, becomes so handsome and tough that it is often used with good results in the finer cordage and in the manufacture of. Due to. T. Its pearl-white filament, above all, becomes so handsome and tough that it is often used with good results in the finer cordage and in the manufacture of. Velhurs-Pearl, Pirt and Luedeking-Piret models during Tonon, R. ; Brabet, C. Influ- pharmaceutical, cosmetic and food industries.