I am using the solution provided here to overlay text onto a PDF.
It works – partially: the text is there (I can copy it and it shows using pdftotext) but is not visible – there’s probably lots of stuff on top of it.
How do I ensure it’s on top, or at least visible?
Add the text after running the input file (that is run the PostScript in -c/-f after the PDF file), or (much better) use an /EndPage procedure to write the text, so that it gets done as the last thing before the page is emitted. See for example stackoverflow.com/questions/12243044/…