One thing I've been debating with regards to the design of the Gentzen typeface is whether or not I should keep most symbols to be strictly geometric or introduce some »calligraphic« flair. For example, consider this test I just tried for the design of a box symbol intended to be used as the symbol for modal necessity:
The weights probably do not match AMS Euler at the moment, but I'll adjust that later. At a very large size, the third version (on the right) does seem slightly plausible, but at smaller sizes on screen the differences are negligible. I'll try seeing how it prints tomorrow. Additionally I worry that straying from geometric shapes will hinder recognition. For example, I also experimented briefly with some variations on a circle to be used as the lax modality, and found anything other than a perfect circle risked being mistaking for a badly done »o«.
So perhaps, some symbols in Gentzen shouldn't try to be too fancy; reader input is welcome. Still it isn't clear offhand whether symbols like the turn-style are safe to make calligraphic or not. More experimentation will be required.