There are a number of things to consider when you are working with type. One of the most often overlooked in typography or maybe misunderstood is kerning. Kerning is often confused with another form of letter spacing, called tracking. Tracking, however is not the same as Kerning.
Tracking vs. Kerning
Kerning, simply put is the adjustment of space between individual letters as opposed to tracking which uniformly spaces the letters of the entire word. A well designed font will come with its own kerning pairs which means, that certain combinations of letters will have different spacing, either in a negative amount or additive amount applied to the default spacing in order to achieve a more pleasing look.
Proportional vs. Non Proportional Fonts
Proportional fonts, will require kerning as their glyphs have differing widths, and as mentioned before any well designed proportional font will come with built in instructions for kerning pairs. Non proportional fonts or mono-spaced fonts are not kerned, as their characters always have the same spacing.
Metric, Optical, and Manual Kerning
Those of you who use Adobe products, may have heard of the term Metric, or Optical in relation to kerning, the difference is simple. Metrics uses the built in kerning values for the various glyphs, whereas Optical allows the type engine to make this adjustment based on the glyphs themselves. Generally speaking if you are unsure of which to use, choosing Optical is often a safe bet. Be sure to check your type palette that your kerning is set to either optical or metrics by default and not “0” or “auto”. If it is set to “0” no kerning will be applied, and this is generally not a good idea.
In the case of most free fonts or poorly designed fonts you will need to manually adjust letter pairs to the best visual result. Kerning issues become more apparent at font sizes 14+ points.
To manually kern, simply place your cursor between the letters you want to space and using the “ALT” or “OPTION” key with either the left or right arrow.
Typical Letters that Need Kerning
It’s important to note that certain letter pairs are real kerning culprits and in the hands of a poorly or designed font, the following letter pairs are the ones most often needing love: AV, LA, P., F., To, Tr, Ta, Tu, Te, Ty, Wa, WA, We, Wo, r., Ya, y. and Yo. Keep in mind that letters aren’t the only glyphs that may need kerning, numbers are often overlooked as well. Some other less common combinations are OA, AC, and FA.