When I mix English and Thai characters in the same document, the Thai characters are very small. I have to manually increase the font every time I write something. I was just wondering if there is any easy way around this. As far as I know, there's no way to set different default font sizes for different character sets. I usually use OneNote, but I think this problem holds true for most document processing programs. 

Did you try the Tahoma or Angsana fonts?

Kinnari actually has Thai characters larger than the the Latin, as the attached image shows.

 

 

Thanks guys. Very helpful. It didn't occur to me that the proportions are different in different fonts. Tahoma looks very good for what I need at the moment.