At size 11, non-bold exclamation mark looks the same as bold exclamation mark.
Created attachment 28647 [details]
Yes, at that size it hints to a two-pix stem width whereas all other
stems (that I’ve noticed & remember) hint to a one-pix stem width.
I suspect this is a rounding issue in the instructions or, perhaps,
in the interpreter(s).
Forgot to say: at 72dpi and ½-pt increments, the extra-wide stem happens
at 11.5-16.0 pts, inclusive, as seen in ftdiff(1).
The fact that at and above 20 or so px/em the ! has a more triangular
shape is probably related.
This seems trivial, but this bug bugs me a lot :) Can someone look into this?