emulatorFont resource

From The x3270 Wiki
Type Default Option
string 3270 -efont

The font used for the x3270 emulator window. By default it is 3270, a 14-pixel clone of a real 3278 display font. Other 3270-specific fonts are available in 8-, 12-, 16-, 24- and 32-pixel sizes. Any constant-spaced X11 font can also be used, provided that it implements a display character set compatible with the host code page. However, the special OIA symbols are only available with the 3270 fonts.