From QB64 Wiki
The _PRINTMODE function returns the present _PRINTMODE status as a numerical value from 1 to 3 in graphic screen modes only.
- current_print_mode = _PRINTMODE[(image_handle)]
- If no brackets and image_handle parameter are given, the current destination SCREEN page or image is assumed.
- If the handle value enclosed in brackets is 0 then the current program SCREEN page is assumed.
- Returns a status value from 1 to 3 designating the current mode setting:
- 1: mode is _KEEPBACKGROUND
- 2: mode is _ONLYBACKGROUND
- 3: mode is _FILLBACKGROUND (default)
- The _PRINTMODE statement and function can only be used in graphic screen modes, NOT SCREEN 0