Posters often write that embedded fonts do not display correctly in Adobe Acrobat or in Acrobat Reader when printed. Following are two jpgs of PDFs that may help to show the issue.
The first image is how the PDF looks when viewed in Firefox. It's perfect!
The second is how it looks when printed to my printer and again when "printed" to Preview, where I could make a jpg. Notice that the embedded fonts do not display. The margins are narrower. And worse, the text does not fit on the page and disappears.
I then downloaded the PDF from Firefox to my computer, opened it in Acrobat, and printed it. It also looked like the first image and was perfect. The embedded fonts displayed correctly; the margins matched; the text fit. This method is called a "best practice" for a reason!
Examining the PDF properties, I also saw that it was created from Pages using Quartz — meaning it was created from File > Print > Save as PDF on a Mac, bypassing Adobe's engine. Adobe does not own PDF technology, and Adobe was not involved in the creation of this document or the PDF—it was only used to view it.
Solution: If you or your clients say the fonts aren't embedded and aren't displaying correctly when printed, then ask if they are printing directly from the browser or downloading first. It makes a difference.