Epson 420i - Manual (Page 41)

Relationship among the font, bold, double-strike and double-width functions is shown
in the table below.
0: Can be used simultaneously x: Cannot be used simultaneously
The bold and double-strike modes may not be entered simultaneously. The last mode
input has priority.
In all print modes, the double-width mode may be used simultaneously with the bold
or double-strike print modes.
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