These settings has been all the time in about:config. Every single setting in Firefox stays in about:config. There was no separate storage for the printer settings.

''<p>TyDraniu [[#answer-1458801|said]]</p>'' <blockquote>These settings has been all the time in about:config. </blockquote> You're missing the point! Easy access to those settings has been removed. I have to wonder why and if that is an indication that all access will one day be removed?

This was changed around Firefox 84 with the introduction of the new print experience combining preview and setup. I don't know whether there will ever be a GUI for custom headers and footers because it is a bit of a niche requirement, but hopefully we won't lose them completely. '''''Migration of Options''''' <img src="https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2021-06-07-09-18-58-5df189.png"> ---- '''''Using about:config to modify left/center/right header/footer content''''' Headers and Footers are split into three parts each of which can contain free-form text and placeholders that Firefox replaces with values computed at print time. The placeholders are: * Title => '''&T''' (placed in Header-Left by default) * URL => '''&U''' (placed in Header-Right by default) * Page number of total (x of y) => '''&PT''' (placed in Footer-Left by default) * Page number (x) => '''&P''' * Date/Time => '''&D''' (placed in Footer-Right by default) Here is how you can update your header and footer content for particular printers or all printers: (1) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.'' <u>''Headers''</u> (2) In the search box in the page, type or paste '''print_h''' and pause while the list is filtered -- you'll see something like the following (the exact number of custom preferences depends on how many different printers you have used) <img src="https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2021-02-21-09-37-00-3b6a65.png"> The following three preferences are the default, but any printer-specific value overrides them, allowing you to customize individual printers: * print.print_headerleft * print.print_headercenter * print.print_headerright To edit a default setting, double-click in the implicit second column (wide area to the right of the preference names before the pencil button) or click the edit button. After making changes, press Enter to save your change, or click the blue checkmark button. To modify a setting for a particular printer (for example, print.printer_Mozilla_Save_to_PDF.print_headerleft), you have two choices: (A) To have Firefox use the default setting, delete the current custom setting using the trash can at the right end of the row for the custom setting. (B) Edit the custom setting as desired. <u>''Footers''</u> (3) In the search box in the page, type or paste '''print_f''' and pause while the list is filtered As with headers, the following three preferences are the default, but any printer-specific value overrides them, allowing you to customize individual printers: * print.print_footerleft * print.print_footercenter * print.print_footerright Edits work the same way for footers as they do for headers.