Microserif is just about the smallest I can go with a serif pixel font. There are smaller fonts than this out there, but realistically speaking, anything smaller than this will not have room for serifs (and if something smaller than this does have serifs, it probably won’t be legible).
Overall, we have:
- 4 pixel tall x-height
- 5 pixel tall cap/ascender height
- 2 pixels below the baseline for descenders
The only real exception is: the tittles of the lowercase i and j go above the ascender height in order to line up with the x-height. With characters this small, you have to choose your battles.
It also would have been nice to get 1 pixel descenders so that the ascenders and descenders would match, but a) not only would this have made lowercase p and q obnoxiously difficult to read, b) I was very happy with the two-story lowercase g that required 2 pixels for the descenders. Again, you have to choose your battles!
Since my height restriction was so strict, I decided not to dwell too much on forcing things to be a specific width. Instead I gave characters extra room if needed and lopped off leading serifs where necessary so that individual letters wouldn’t be too wide. The widest character is capital M (and capital W) which are the usual offenders anyway.
It might seem strange to say about such an unassuming font, but I’m very, very pleased with how this turned out. I think this is one of my favorites!