How about using a more appropriate application for printing those name badges? Like maybe a Word Processor application like Microsoft Word.

Without getting into a long explanation, Firefox doesn't use those Printer preference settings directly; Firefox has its own Print dialog windows which are appropriate to internet activities and doesn't handle word processing type files too well. It can be done when you know the "tricks", but for the time expended its a waste of time when using the appropriate application for the content is far easier.