Thanks Michael. I'll see what I can do. If I find a good solution I'll post another message here later in case anyone else encounters this effect.
Regards,
Fleetfoot

So, for what it's worth, the fonts don't look strange for me anymore. I switched from Linux Mint Cinnamon to Linux Mint XFCE, reinstalled PlayOnLinux, and now everything is fine with the default version of wine (before I had to go to 1.4.1 to avoid blocky-looking fonts). I also tried 1.6.2, which was giving me problems before, and that one works fine too. So, I don't know if that's really helpful for anyone, but at least it's working for me.

A year later, I think I've found the definitive solution to this text rendering issue without having to resort to an old version of Wine. If you look at the Wine FAQ (http://wiki.winehq.org/FAQ), section 10.12.6, there is a blurb about missing or corrupt text with QT applications. The fix is to apply a registry edit as described in the FAQ. Put the following in a file (e.g. norender.txt):

[HKEY_CURRENT_USER\Software\Wine\X11 Driver]
"ClientSideWithRender"="N"

and then run WINEPREFIX=/path/to/MoI/base/wine/directory regedit norender.txt

This sounds like it changes the font-rendering method. This fixed the problem for me on Wine 1.7.50.

I just installed v3.0 on Mint 19 and had the exact same problem as fleetfoot, it looked exactly the same.

I solved it by installing the component Mono210 with playonlinux.

Everything seems to look and run fine now.

Hi Kevin,

re:
> I solved it by installing the component Mono210 with playonlinux.

MoI doesn't actually need any .NET / Mono stuff itself but probably your installation had a side effect of setting a Wine setting as described above:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4409.103

- Michael