Abstract: An composite prepreg ply which can be designed to exhibit desired electrical properties without loss of structural integrity or the addition of parasitic weight, and a method of preparing the composite prepreg ply. The composite prepreg ply includes: (i) a low dielectric cloth substrate having a metal layer adherent on both sides thereon, the metal having been selectively removed from at least one portion of at least one side of the cloth, such that there is at least one area of cloth without any metal adherent thereon; (ii) a layer of encapsulant resin material adherent on the metal layer; (iii) a resistive resin layer containing a filler material dispersed in a carrier resin, the resistive resin layer adherent on desired areas the cloth without any metal adherent thereon, and (iv) an impregnating resin covering one or both outermost surfaces of the encapsulant resin material and the resistive resin layer.