This object informs the printer what size of envelope is
currently loaded in the envelope feeder. Because the input tray
feeding envelopes may not have a size sensor, this setting is
required so that the printer is able to know when the size of
envelope requested for printing is different than that loaded.
When the sizes do not match, and xcmPrtInterpPageSizeErrorPolicy
is set to Off, the printer displays a message asking for a
change of envelope size.
The XcmPrtPaperSize selected should be that of an envelope.