I installed the Charis SIL fonts from here:
http://scripts.sil.org/cms/scripts/p...isSIL_download I used the .exe file--the windows installer and it installed the fonts in the font file on my computer. I then did a copy and paste into the fonts file on kobo.
They read like this CharisSIL-B.ttf. In other words like the example I used above. I have not played with Johns version.
They work well in kepub. Bold works etc. They are pretty icky in ePUBs.