Psdir

The set psdir directory command controls the search path used by the postscript terminal to find prologue.ps and character encoding files. You can use this mechanism to switch between different sets of locally-customized prolog files. The search order is
     1) The directory specified by `set psdir`, if any
     2) The directory specified by environmental variable GNUPLOT_PS_DIR
     3) A built-in header or one from the default system directory
     4) Directories set by `set loadpath`


Anton Gladky 2016-02-19