I'm designing a typeface family with three optical sizes (36pt, 72pt, and 144pt) and a few layerable weights per each optical size. I've been experimenting with how I can make each weight line up when layered on top of each other and I'm starting to pull my hair out.
I thought having the same width and left/right sidebearing info would be enough, but that's not the case. Since the weights aren't the same width (I have a regular weight and a 3D weight, for example), having the same metric info results in them not lining up.
I've been trying to reverse-engineer fonts that do this, such as Frontage. I've opened up a few of the Frontage weights and the characters seem to have different widths, left, and right sidebearing data (picture below). It almost seems like the designer had to line them up manually (can't see this being the only option...).
Anybody have any ideas on how I can accomplish this? I'm at the point of giving up because I can't see any feasible way of doing this.