Abstract: Magnet wire substrates (1) are described having a layer of polyester tape (2) wrapped thereon, including a layer of spirally wrapped and bonded polyester insulation tape (3) as the outermost layer. The two tape layers are made up of amorphous (4) and crystalline (5) segments unbonded to the wire and bonded to each other to provide the requisite electrical properties and improved physical properties including increased flexibility and ease of strippability. A single multilayer polyester insulation tape can also be used with similar properties and reduced thickness.

Abstract: Optical glass fibers are provided with a primary coating of organo-polysiloxanes, containing acrylic acid ester groups, corresponding to the general formula: ##STR1## where the primary coating is free of inert components capable of migration.