I've used Firefox as my default browser for years on my PC (Windows 10), never had this problem: Two days ago everything I printed from Firefox started printing in tiny print. After sleuthing, I found that my default print scale size (as seen in the Print Preview window) had defaulted to 30% (I normally leave it at Shrink to Fit). And even the title of that percent window changed from "Scale" to "ShrinktoFit". The problem is that I can't change it out of 30%! When I choose another percent or Shrink to Fit in that Print Preview window (as I've always done for years when I want to change the print size for a particular job), it doesn't hold; next print job it's right back to 30% and tiny print. I went to the Firefox "How to fix printing problems" page and followed all the instructions (including the about:config fix), I have restarted Firefox multiple times including in Safe Mode (with all Add-ons disabled), I finally uninstalled Firefox completely on my PC and then downloaded and reinstalled it again, but still the print size is stuck at 30%. And that's for anywhere and anything I print on the internet in Firefox (my Yahoo email, any and all web pages, etc). I tried downloading Chrome and printing the same test web pages from Chrome and they come out fine. So it appears to be some glitch with Firefox on my PC. Any ideas what's wrong?