3M polyester film electrical tape 56 is a general purpose polyester tape with thermosetting rubber adhesive. Designed for insulating applications requiring a thin, durable tape with high dielectric strength. It can withstand higher-temperature conditions than tapes with acetate cloth backings. By heat curing, the thermosetting adhesive can be made to resist common industry varnish solvents. 3M polyester film electrical tape 56 is designed for insulating applications requiring high dielectric strength with a thin, durable film backing. It has a rubber thermosetting adhesive coating and a low adhesion back size coating which makes it suitable for automatic taping. It is used in applications of coil outerwrap, inner-layer insulation, capacitor wrap and assorted other holding applications. The thermosetting rubber adhesive is aggressive and suited for adhering to oily magnet wire.