Suppose I have a 2-axis 4-master variable font, say with wdth and wght axes, so narrow/light, narrow/bold, wide/light, and wide/bold masters. Let’s say master values are at 0/0, 0/100, 100/0, and 100/100.
If I want to add an optical size axis, but want to limit uses of it to narrower ranges of width and weight, what’s the proper setup? I’ll add an opsz value of 48pt to those preexisting masters, then:
Option one: Set those corners of the design space in from the extremes, eg. to 30/20/8pt, 30/80/8pt, 90/20/8pt, and 90/80/8pt. Essentially making not a cube but a trapezoid (or whatever the three-dimensional equivalent is called).
Option two: Generating the same designs as option one, but setting them to the extreme positions to get a proper cube. So what looked like 30/20/8pt is placed at 0/0/8pt, etc. This would mean changing the opsz slider would change the weight/width even though those sliders stay put, I think.
Option three: Design the masters at those extremes even though they’re beyond what I want people to use at small opsz, and find another way to constrain user access to them (so they live in the font but won’t be used). Could axis mapping do this?
Option four: Design the masters at those extremes even though they’re beyond what I want people to use at small opsz, and learn to live with people misusing them.