for the uninitiated you use these on your plots etc by including !fontnum_letter!X (remove underscore) i.e. xtitle=' !7l!X ' brings you to font 7(Complex greek) and the letter 'l' gives you mu as in micron.
Trace: • astrocds_astronomy_career_development_seminar • spring_2019 • steve_dawson_s_diy_idl_fonts