4.8.2 Controlling the font used in the terminal window

This option allows you to choose what font, in what size, the PuTTY terminal window uses to display the text in the session.

By default, you will be offered a choice from all the fixed-width fonts installed on the system, since VT100-style terminal handling expects a fixed-width font. If you tick the box marked ‘Allow selection of variable-pitch fonts’, however, PuTTY will offer variable-width fonts as well: if you select one of these, the font will be coerced into fixed-size character cells, which will probably not look very good (but can work OK with some fonts).