I want to create a variable font with multiple instances. But I currently don’t know how to set it up with the masters + exports + axes.
I currently have 2 Masters. Regular + Bold with 2 Interpolation steps so in total 4 fonts (Regular,Medium,Semibold,Bold). This is the instance „Weight“.
Now I want to add another instance „rounded“. Here I want to add rounded corners, so from 0 to 100 for example.
You will need more masters for that. Ideally, two more: Regular Rounded and Bold Rounded.
The question then is how you make those compatible (interpolatable) with the unrounded masters. If you round the corners in your rounded masters, you will need to guarantee the same path structure in the unrounded masters.
You will probably end up doing something like this:
On the right, you can see that the path visually has a sharp corner. But in this corner, there are the same number of nodes as on the left (two oncurve nodes as well as two offcurve nodes in between). This way, you keep your paths compatible.
By drawing TrueType directly, you have another option. Habe a look a the file. The “H” has TrueType curves and the “I” uses the approach explained above. The round state is identical. But the “I” might be better at the beginning if the interpolation (when there are smaller round corners) and the “H” might be nicer closer to the round end.