Abstract: A welding or additive manufacturing power supply includes a user interface that receives a user input shielding gas mixture comprising separately adjustable amounts of a first and a second shielding gas. Output circuitry generates a shielding gas customized welding waveform. A memory stores a first plurality of waveform parameters that are associated with the first shielding gas, and a second plurality of waveform parameters that are associated with the second shielding gas. A controller is operatively connected to control operations of the output circuitry, and is configured to determine a third plurality of waveform parameters at least partially defining the shielding gas customized welding waveform. The controller determines the third plurality of waveform parameters from the first and second plurality of waveform parameters and the amounts of the first and second shielding gas.