Abstract: A foil has two essentially plane parallel surfaces of which at least one is at least partially covered by a metallic layer. The surface of the metallic layer is protected by an antifriction film. The surface opposite the metal-coated surface of the foil can likewise be protected by an antifriction film. The antifriction film or films should have a uniform thickness of at most 0.5 micron. The antifriction film or films can be vapor deposited, rolled or sprayed on to the foil or distributed on the foil ultrasonically or electostatically. The foil is subsequently wound into a roll.

Abstract: A method for the insulation of a hot metallic material which is heated for hot working is described, which comprises applying a mixture of acidic aluminum phosphate, e.g., aluminum hydrogenorthophosphate, a multivalent metal oxide, hydroxide, silicate or carbonate powder, and water onto the surface of the hot metallic material and allowing the mixture to be heated by the heat of the hot metallic material to convert it to a porous hardened material. The porous hardened material acts as an insulating coating layer for the hot metallic material, permitting hot working in an insulated state for a long period of time.