Comment 126 for bug 10910

The evil print.postscript.paper_size letter default comes from bug 125078 and
I don't see any means provided for changing the default.

initPrintSettingsFromPrinter was meant to get setting from the printer and the
xprint backend implementation appropriately asked the system for available
paper sizes. It seems print.postscript.paper_size pref was just a space
filler for lack of a postscript implementation.

savePrintSettingsToPrefs and printer-specific prefs in
initPrintSettingsFromPrefs weren't added until bug 128142 and they now seem
the appropriate place for managing preferences.

So I agree that it is better to leave the paper settings at their default than
to pull in this arbitrary default.