Fixing fonts that display wrong in a PDF

When a PDF shows the wrong typeface — or boxes where letters should be — the cause is almost always a font that was not embedded.

The root cause

If a font is not embedded, the reader substitutes another, changing appearance and spacing. Missing glyphs show as boxes or blanks.

The fix at the source

Re-export the document with fonts embedded (a checkbox in most exporters). This is the proper cure.

When you only have the PDF

Flattening the pages to images guarantees the text looks right for viewing and printing, at the cost of selectable text.