fibrous wrapped insulation
Electric wire surrounded by organic fiber-based insulation; types include circular loom, insulating paper, insulating thread, rubber insulation, varnished cloth; forms include felted material, paper, thread, woven fabric, or yarn; treated with gums, oils, varnishes, or impregnating compounds to increase moisture, heat, and shrinkage resistance; first used in 1879. (Bucher, 1996)