The diamond paper is made of high-strength insulating paper printed on both sides in a diamond pattern with “B” stage epoxy resin. Since the diamonds are spaced apart, the unprinted surface corresponds to 64%, in this way secure adhesion of the insulation to the conductor is guaranteed. Furthermore, the pre-preg resin of the diamonds reticulates passing from state B (pre-preg) to state C (polymerized) anchoring itself firmly to itself or to metal parts with which it comes into contact, creating micro-channels for optimal oil circulation. All thicknesses are thermally upgraded.