Monospace Font Spacing

Monospace fonts are distinct from standard kerning fonts. I researched numerous mono fonts on the market while spacing monospace font. It raised some questions and doubts, and I'm experiencing some difficulties with monospace design spacing. The width of the matrices is the same for all glyphs, however the glyphs are not centred in the matrices. Some have irregular spacing on both ends (RSB and LSB).
The following are the questions:
  1. What is the standard accepted method or practise for adjusting the spacing or side bearings of monospace fonts?
  2. How do you determine equal spacing between all glyphs in a monospace font?
  3. How did the designers arrive at the precise quantity of RSB and LSB in monospace font?
  4. What are your biggest pain points and sensitive areas while spacing mono fonts?
  5. What guidelines do you follow while spacing mono fonts?
Your input would be incredibly valuable to me, and I would be most grateful for any guidance you might be able to provide. I cannot thank you enough for your time and consideration,

Mithil Mogare
(+91) 8888 24 1144


  • Craig Eliason
    Letters (other than quite symmetrical ones) are not centered in their advance width (i.e. have different sidebearings) because mathematically identical sidebearings will not result in optically even spacing. An L or an r for example is heavy on the left side and quite open on the right, so with mathematically even sidebearings it will look like it's crowding the previous letter and too far from the following letter. 
    Since this is an optical rather than mathematical effect, the solution lies in optical judgment rather than mathematical formula. Once satisfying, symmetrical sidebearings are set up for a letter like H (and after considering the advance-width decisions John mentioned above), it can become a "control character." Then you can type a string like "HHLHH" and skootch the L sideways so that it looks centered to your eye. 
    (In the font editor, with a monospace design you obviously want the advance width to stay constant, so instead of adding units to one sidebearing and then subtracting them from the other, it's easiest to select all the paths and move them sideways at once.)
  • Nick Shinn
    Nick Shinn Posts: 2,169
    edited February 2023
    Here’s a good test word: mammillaria
    Also: Ammunition
    And: David Hemmings

    I’m sure you can find some words that you like—in fact, searching for “worst case scenario” test words, and comparing your design with other monowidth typefaces, in such words, can be quite interesting and useful.

    I just googled “double m words” and came up with a Scrabble list, that’s where I found “mammillaria”. Then I wondered what it meant, and checked Wiki. You learn something new every day!
  • Johannes Neumeier
    Johannes Neumeier Posts: 365
    edited February 2023
    While on the subject of test words, here a couple of mono-space tricky samples from Finnish, which has a bunch of uncommon (in English anyway) double-vowels and double-consonants:
    niinikään miinanraivaaja uutisvaahtimme puuttellinen puutiikki pellavaliina kukkaruukku …

  • Craig Eliason
    Now I'm pondering: does using foreign or otherwise unfamiliar words lend a "defamiliarization" effect that makes it easier to see spacing issues? Or if I have no pre-existing sense of what the word should like is it instead harder to see them?