Letter Spacing

In typeface design attention must be paid to two main issues: the space within characters (the counters) and the space between characters. For all characters, the counters should have the same optical value. Similarly the spaces between characters shouls have the same optical value with the counters. This is required to achieve an acceptable word-image.

Each letter is designed with a set-width. Sometimes with certain letter pairs it may be necessary to modify the set-width to improve the word-image. This is called kerning. Below on the left the pair of letters ac are kerned whereas on the right they are not.

Ligatures

The design of a specific typeface may lead to collusions with certain letter pairs. Ligatures (combined letters) can provide a solution. Majority of typefaces provide ligatures for most common problematic letter combinations such as the pair fi. However note that this is a language dependent problem and for example the ligature below does not work for Turkish.