I am not a fan of the default header and footer settings that Firefox uses when printing. Too much info, most of which I do not care about. Like having the URL of the website. If I need it again, I have it bookmarked or a quick search for some keywords from the content should be sufficient. If I am printing it on paper, I don’t care about the URL. Same for the date and time. Some people (perhaps in business) may need this sort of info on their printouts, but I don’t need it and don’t want it.
Changing the header and footer info that is printed is very easy. The problem is that it resets after every print job. I have looked occasionally but never found a GUI way to change the info and have it stay changed. So today I delved into about:config. Sure enough, it isn’t that hard to do if you are willing to poke around “under the hood” a bit.