Need a parameter for joins

[bensyverson]

One of the most important characteristics of a sans is the way arches and curves join their stems. This should definitely be one of the primary style variables alongside Thickness, Contrast, etc.

Currently, there is no way to adjust joins, and some characters (such as the /a in Grotesk) have excessively stylized forms:

I imagine the Join parameter could go from being curved from the stem (Proxima Nova /a, Avenir /b & /n) to nearly perpendicular (News Gothic).