When going thru Print Preview the "selected text" becomes unavailable.

If you want to print "selected text" use { Ctrl + P } to initiate printing rather than the "Print" button.

Do you have a PDF printer driver? Some PDF-related programs include one, but if you haven't purchased one of those, you can install a free one.

The reason I suggest that is often a selection print has unexpected problems, such as part of the text being outside the margins. Having a PDF printer option can reduce paper waste when trying to figure out the best selection.

PDFCreator is a free open source program; you can decline their additional free software that may be included in the installer:

http://www.pdfforge.org/pdfcreator

When you print, you can change from your real printer to the PDFCreator printer in the print dialog, and change it back for "real" paper.

Another useful tool for printing only portions of a page is this add-on, which adds editing tools into the Print Preview screen:

https://addons.mozilla.org/firefox/addon/print-edit/

This is a glitch that occurred for me after installing 49.0.2 on 10-21-16. The Print Selection Only option always worked before, so something is clearly wrong as a result of the update. It's imperative to be able to just print the selected text versus an entire document. Please fix this asap Firefox. Thank you!

Hi youngjane1118, since the Mac print dialog is totally different from the Windows print dialog, I think it's best to address Mac issues in your new thread here: https://support.mozilla.org/questions/1144207