[rspeer]

Ah! Knowing that, I bet that someone _could_ make a CJK font optimized for file size, which includes radicals by reference. It wouldn't work in every case, because radicals change size and strokes shift to make room for other strokes. In cases where the same radical appears in the same place, it seems like it would help.

But maybe that's not enough of a benefit unless there's also a way to say "okay you need to use this radical, but a bit narrower, but the strokes need to be the same width and not distorted".

[davelab6]

The www.glyphsapp.com and www.fontlab.com font editor apps have "smart components" which do this. Sadly the OpenType format is developed very conservatively by Microsoft so these aren't part of the only widely supported font format today, despite recent additions to the format of run time interpolation technology.