Since Internally TrueType fonts are rendered by locating a font specification file you must install the accompanying TrueType fonts in directory of your choice. You must then tell JpGraph where these fonts may be found by specifying the font-path in the FONT_PATH define (in jpg-config.inc.php). Please note that this must be the absolute file path and not relative to the htdocs directory. By default the path is set to
DEFINE( "TTF_DIR", "/usr/local/fonts/ttf/");
Since JpGraph must be able to tell the difference between the italic and bold versions of the same font family a standard naming convention is used to name the files. The available fonts are also defined by DEFINES and hence you can't just copy your own TTF files to the directory and expect it to work. At the moment there is no "easy" way to add new fonts but to make some (small) mods to the code. However this is expected to change in future version of JpGraph.