[Tex/LaTex] Basic kerning with XeTeX


Trying to use custom fonts with LyX, so I started using XeTeX.
Unfortunately, It seems kerning only works with certain OpenType fonts (Linux Libertine) but not for others (Doulos SIL or Charis SIL).

Are there additional settings I have to set up in order for this to work?

Edit: Images from the pdf output (with Linux Libertine and Doulos SIL respectively):
Kerning with Linux Libertine
No kerning with Doulos SIL

Best Answer

(This is a combination of my and Ulrike's comments.)

Kerning is activated by default. If you don't get kerning you either deactivated it somehow (see documentation of fontspec for information) or your font doesn't have the kerning information (or uses rather small values).

From this page here: Unicode IPA fonts it appears that the SIL Doulos and Charis fonts have no kerning pairs. This fact isn't too surprising since they were designed primarily as phonetic fonts for which kerning doesn't make a lot of sense.