gtk:print-settings-printer-lpi (settings)

settings -- a gtk:print-settings object
lpi -- an integer with the resolution in lpi (lines per inch)

The resolution in lpi (lines per inch). The gtk:print-settings function gets the value of the "print-lpi" setting. The (setf gtk:print-settings-printer-lpi) function sets the values of the "printer-lpi" setting.