A font’s spacing (between words, letters, punctuation, etc.) should be balanced, consistent, and optically correct.
Any problems with letter spacing issues should NOT be fixed by adding kerning pairs. First, get your basic spacing right. Adjust the sidebearings of each glyph. Only add kerning as a second step, wherever exceptions for specific pairs are necessary (see below).
Has the spacing been approached in the right way in your font? Generally, a glyph like ‘o’ should be optically centered in the middle of the glyph space, with an equal amount of white space to its left and right.
Is the spacing systematic? Equal shapes should be treated equally.
- Glyphs App - Spacing
- FontLab IV - Spacing and Kerning
- Typeworkshop - Spacing – “Defining the rhythm is more important than defining the shapes.”
- Fontforge - Spacing, Metrics and Kerning
- G. Briem - Spacing
- Adhesiontext – Miguel Sousa’s tool lets you generate a custom text string for testing the spacing, among other aspects.