3M 1245 tape consists of an embossed 1 oz deadsoft copper foil backing and an aggressive pressure sensitive acrylic adhesive. The edges of the embossed pattern pressed into the foil cut through the adhesive layer to establish reliable metal-to-metal contact between the backing and the application substrate. - The backings of shielding tapes 1245 (copper) are impressed with an embossed pattern that protrudes through the acrylic adhesive to make direct electrical contact with the application surface. This reliable through-the-adhesive conductivity system provides stable contact resistance and a high level of shielding effectiveness.