X3270/Fonts

x3270 uses XLFD fonts to render its display. These fonts are an archaic technology that is slowly disappearing from Linux distributions, but they are still used by common tools like xterm.

x3270 includes its own proprietary XLFD fonts:

The x3270 fonts use a proprietary encoding, and generally cannot be used with other applications.

x3270 can also use any constant-spaced XLFD font that implements a character set consistent with the host code page. For example,  (Unicode) fonts are generally compatible with any host code page, except for the display of DBCS characters.