When tplot plots are saved as postscript files, sometimes the text elements don't convert well. He thinks the issue might have something to do with vector vs. hershey vs. truetype fonts, especially for Greek letters and other symbols. There is a Coyote Graphics library routine that can check for problematic characters, and replace them with equivalents that look better in postscript. He will send us more information for reproducing the issue, and the CG routine to fix it.
From Arthur Hull at AGU:
When tplot plots are saved as postscript files, sometimes the text elements don't convert well. He thinks the issue might have something to do with vector vs. hershey vs. truetype fonts, especially for Greek letters and other symbols. There is a Coyote Graphics library routine that can check for problematic characters, and replace them with equivalents that look better in postscript. He will send us more information for reproducing the issue, and the CG routine to fix it.