I can't recall without looking into it, but there's a lot of gotchas when implementing web fonts. You have to ensure it's using fallbacks, that it can use them

I can't recall without looking into it, but there's a lot of gotchas when implementing web fonts. You have to ensure it's using fallbacks, that it can use them before the target fonts have loaded, that the fallbacks are close to the web font in style, and there's a bunch of CSS tricks you can use so that a repaint doesn't end up reflowing everything.