The original design space of Adobe Variable Font Prototype was made up of four masters arranged along two axes — weight and contrast — as illustrated by Figure 1.
Figure 1: Original design space
- m0 — Extra Light
- m1 — intermediate master near the Regular instance
- m2 — Black
- m3 — Black High Contrast
This arrangement of masters produced a fully functional area (marked in green). But at the same time defined another area (marked in orange) that exposed unusable results, such as the instance seen in Figure 2.
Figure 2: An instance from the orange area of the design space
To conceal the orange area of the design space, we used two additional masters that better delineated the boundaries of the usable area of the design space. The first step required generating an instance at the intersection defined by the diagonal between m0 and m3, and the vertical drawn from m1. That instance was then introduced into the design space as m4 (master_4), as shown in Figure 3.
Figure 3: Creation and introduction of m4 into the design space
The second (and last) step consisted in reusing m0 at the vacant corner of the design space.
Figure 4: Existing master m0 is used twice
And that’s it. With the additional two masters the triangular green area got stretched to a rectangular shape, filling in the whole design space.
Figure 5: Final design space
Figure 6: Another way to visualize the final design space