User Guide

Multiple Master Fonts
591
Extrapolation
The Multiple Master font specification allows only interpolation of the
master designs to define an intermediate font. In addition to that basic
feature, however, the multiple master font structure allows linear
extrapolation of the designs also. This feature allows us to artificially
extend the design range of the MM font, which sometimes produces
interesting results:
Standard dynamic range for the Width axis
Extrapolated range for the Width axis
Extrapolated Weight
In real life this feature lets you extend font families with very little effort:
for instance, build an MM font using the normal and bold styles and then
add light and extra bold using the extrapolation feature.