A transaction card, and processes for the manufacture thereof, having a core layer, optionally, one or more layers or coatings over the core layer, and at least one of a magnetic stripe, a machine readable code, and a payment module chip disposed in or on the card and suitable for rendering the card operable for conducting a transaction. The core layer comprises a metal-doped cured epoxy comprised of metal particles distributed in a binder consisting essentially of a cured, polymerized epoxy resin, the core comprising greater than 50%, preferably greater than 75%, and more preferably greater than 90%, of the weight and/or volume of the card. In some embodiments, the core includes a metal insert enveloped with the metal-doped curable epoxy, wherein the periphery of the epoxy extends beyond the periphery of the metal insert and has material properties more conducive to cutting or punching than the metal insert.