(Untested) In PrinterPreset: ppd any r/w The PPD, specified as a PPD name or an enumeration. Can return: PPDValues enumerator or String.
The only available
i defined
value in PPDValues is "DEVICE_INDEPENDENT", so all other values should be supplied as a string.
It is a read/write value, so the regular way of checking what this string should be, is to first set your wanted option, then read it so you know what the string should look like. Most likely, however, it's just the full name of the PPD: "PrinergyRefiner".