In reply to Vertical Dimensions of Adobe's Source Sans Pro:
In FF Ernestine* there's an increase of 4 units (Em = 1000) between each of Light, Regular, Demi and Bold, for each of: x-height, cap height, ascender height and descender depth. People seem to agree that lining up the baseline remains sacrosanct, even in a text face. In display typography lining things up is much more important.
I agree with John that going the other way with the caps is peculiar, but maybe it's this: cap diacritics -which go over the em a good deal- might need more room the darker they get.
hhp
