A plasma arc torch both cutting and marking of metal workpieces includes a plasma nozzle having a plasma nozzle orifice through which an electric arc from an electrode and a stream of plasma gas are emitted toward a workpiece, and a liquid-injection shield cup that injects liquid tangentially inwardly to the arc and stream of plasma gas. A power supply is operable to selectively deliver electrical power to the electrode at either a low power level suitable for marking of a workpiece or a high power level suitable for workpiece cutting. The torch may be selectively operated to mark at the low power level, with a plasma marking gas being delivered to the plasma gas passage, or to cut at the high power level, with a plasma cutting gas being delivered to the plasma gas passage, and liquid being delivered to the liquid injection passage for both cutting and marking.