Originally Posted by ShellShock
Thanks - very interesting indeed! Fontin used to be my favourite font, until I ran into this ligature problem on the Kobo. In fact, after reading your post I have checked again and "officer" is being rendered as "o cer", i.e., it is using the ffi ligature and not ff as I initially thought (in the source epub there are no ligature characters). I may add the ffi ligature to Fontin to get around this problem. In fact Fontin is the only font I have found so far which has this problem, especially with the word "officer" (common enough in the military history fiction I tend to read).
In one book I read, a major characters last name was ffolkstone. Of course, the ff ligature at the start of the name represents a capital F and there is no Ff or FF ligature to use in that spot but to some, it looked strange not to have a capital letter at the start of the name.
Also attached a copy of the modified font tester file as modified and sent back to me.