When I hear the term Modern in the context of a typeface design, a very clear image of what that looks like comes to mind. I also associate it with its own history, geography, etc.
The same goes for the term Scotch.
However – undoubtedly because the latter evolved partially from the former – there are many typefaces which I might term either way. In my head there is this kind of scale between Modern and Scotch that looks something like this:
So, my question (lightly aimed at Nick Shinn) is this: What are the lines between Scotch and Modern? Are all Scotches (Scotts?) necessarily Moderns? At what point is a typeface beyond-a-doubt Scotch or non-Scotch?
Knowing a typeface's origins and design history tends to bias my distinction on a case-by-case basis, so I'd be curious to get more of an understanding from a purely formal approach. Specific examples would help a lot too.
Perhaps this is an issue that can't be nailed down with 100% precision, but if it could, I'm sure it would happen here.