Raspa is split leather, the inner (flesh) layer of hide after being stripped away from the topmost layer. This is actually defined by law in Brazil (see http://www.soleis.adv.br/couroecalcados.htm). It's most commonly used to make welding gloves and aprons, but blankets (for draping over machinery or spark-sensitive equipment) are also available. See, for instance, http://www.discountsafetygear.com/wilson-welding-blankets-me...