Films make especially thin, rip-proof adhesive tapes possible. But there are even major differences when films are used as the backing material for adhesive tape. It depends on what they are produced of: PolyVinylChloride (PVC), PolyEthylene (PE), PolyPropylene (PP), PolyEthylene Terephthalate (PET) or another material.
PVC, for example, can be soft and is suited primarily to insulation applications and masking, for instance during plastering works. Very soft PVC is intended for insulating cable covers. Hard PVC, by contrast, is primarily stable in form and is used as packaging adhesive or for interior packaging. All PVC films share the fact that they are durable and do not ignite easily. They can be printed and embossed.
PE or PP films are used as backing for tesafilm® and other office adhesive tapes. They are also in demand as surface protection or for bundling materials (strapping).
Very different properties are involved in PET films. They primarily form the backing between two primers in double-sided adhesive tapes. Since they conduct heat, they are suitable for heat management in electronic devices. Their UV stability makes them attractive for exterior applications.
Besides the mentioned uses, polyurethane, polyimide, and cellophane/cellulose acetate are used in film backings, in particular because they are very elastic, weather-proof and immune to very high temperatures.