I'm working on Ubuntu 16.06.7 LTS X Mathematica 12.1.1. Very recently, special characters do not display correctly anymore once exported to pdf. Here comes a basic working example:
figure = LogLogPlot[x^2, {x, 0, 1}, Frame -> True, FrameLabel -> {{"\[Rho] [g \!\(\*SuperscriptBox[\(cm\), \(-3\)]\)]",
None}, {"x [cm]", None}}]
Inside Mathematica, the output displays correctly:
When exporting to pdf,
Export["figure.pdf", figure]
special characters, including Greek letters and exponents, do not display correctly anymore, in the exported file:
The problem occurs when exporting to pdf or eps, but not when exporting to png or jpg. This may seem a detail, but its quite annoying when producing publication quality plots.
I would exclude the following hypotheses:
- the problem is not inherent to FrameLabels, it also shows up in PlotLegends, and Graphics[Text[...]].
- I tried different fonts (Times, Arial, Helvetica), the problem persists.
- the problem is neither inherent to the OS or pdf viewer. Pdf files generally display correctly on my computer except those produced by Mathematica.
- pdf exportation with other programs (firefox, chrome, texmaker,..) works smoothly.
Any help would be appreciated!

pdfandepsformat). – Ben Izd Mar 20 '21 at 17:46