Kelvinch - a font for body text.

That’s why OpenType Features should be used for ligatures. The text string doesn’t change — it will still be “ct” or “ff” but when an OpenType aware application finds those strings it will replace them with ligatures.

The ct ligature should be a Discretionary Ligature (dlig) unless you’re creating an archaic font, and the “ff, fi, ffi, fl, ffl” ligatures should be Standard Ligatures (liga)

There’s a tutorial on Panose Classification. I don’t think it’s important to get it 100% right. Most fonts don’t include this information. All I do is copy the Panose number from a similar font that does have it, and paste it into the Font Properties dialogue.

The number for Gentium is 2-0-6-6-8-0-0-2-0-4