I'm trying to write my own PostScript file manually and want to use a custom TTF font downloaded from the web but it's not using it - either uses some other font or doesn't display the text at all. I don't have problems with the fonts installed in the system.
The commands I used were different variations of:
/FontName /TheFontName def
/TheFontName 20 selectfont
(XXXXXXXXXXX) show
You can't use a TrueType font directly in PostScript, unlike PDF PostScript doesn't support TrueType.
In order to use a TrueType font you must first convert it into a type 42 font which PostScript does support.
Adobe Technical Note 5012 documents the type 42 format