An RFID tag may include an antenna substrate comprising a conductive layer etched or deposited to form an antenna, and a circuit substrate comprising a conductive layer etched or deposited to form a circuit, the antenna electro-magnetically coupled to the circuit. An RFID tag may be formed from an insert substrate comprising an insulative layer between two conductive layers, one of the conductive layers etched to form an antenna and the other conductive layer etched to form a circuit. The insert substrate may be received in an envelope formed by a label substrate, which may carry a pressure sensitive adhesive.