-noborder command-line option

From The x3270 Wiki

Causes a the wx3270 window to be created without a border. This removes the usual window controls -- maximize, minimize and close -- and prevents the window from being moved. Its primary purpose, along with the -nobuttons command-line option and specific restrictions, is to run wx3270 in kiosk mode, where users are unable to modify the appearance or operation of the emulator.

Examples

Start wx3270 with no window border.

-noborder