Cool retro font :-) It would be nice in a game or graphics.
BTW: in sample.png the thicker border seems to be asymmetrical (the thickness goes inside on the left-side, but outside on the right-side). Is it intentional?
Author here, after noticing the influx of views from lobste.rs. It’s not intentional, but there’s no good way around it, either. The thicker (2px) border is actually centered perfectly, it’s the thinner (1px) border that’s offset; Cozette is 6px wide, so the thin border must be one pixel off to either side. The alternative would be to make the borders obscenely (4px) thick!
I see that there is only one vertical bar (not left and right), so it needs to be asymmetrical* or odd number of pixels wide. The 2/4px would be too much. I tried in a bitmap editor how it looks 3px thick and it was quite heavy (but not that bad as 4px). The 2px version looks prettier – at least until you spot the 1px offset imperfection on the right side. I am not sure which version is better or less worse… maybe people should use rather single or double borders and use the thick ones only if they want it really heavy :-) e.g. the box-drawing character example at Wikipedia is symmetrical.
*) I mean it relative to other borders, not to the bitmap matrix (6px wide characters as you say).