a traversed package is formed from a tape which is slit from a laminate composed of a metallic foil layer and a dielectric insulating layer of plastic film , with a longitudinal edge or edges thereof folded back against the surface of the tape . the packaged tape can be applied to twisting conductors in a cabling process either helically or longitudinally with the folded edge or edges preventing the foil layer from electrical contact with adjacent conductors or shields .