I designed the HTML and CSS templates for a friend who uses Prince to generate article PDFs. Yesterday, he reported a long-standing issue:

Sometimes, he has to open a PDFs in Acrobat to make a change. After making any change at all, the text in the @top-right and @top-left margin boxes often gets distorted, with some characters being replaced by boxes. I checked it out, and the font is Times New Roman both before and after. Could there be some encoding issue that Acrobat is choking on?

I don't have Acrobat, so I can't run extensive tests. But if someone could offer any insight into this issue and any possible workarounds or troubleshooting steps, I'd be immensely grateful. Thank you!

P.S. In the examples I've seen, the characters replaced by boxes are all plain ASCII characters—not ligatures, nor special characters like á or ç or anything.

Perhaps try disabling font subsetting when generating the PDF?

Thank you, @mikeday! We'll give it a shot.