Tracking and Kerning
Tracking and kerning refers to the adjustment of space between individual letters. In leading desktop publishing programs, such as PageMaker, you can set tracking anywhere from very loose to very tight. Kerning allows you to manually adjust the space between individual pairs of letters.
If you tighten the track, the amount of space between letters will be reduced, and you can fit more characters on every line. (Roger Parker suggests that you try to fit between 40 and 60 characters per line. He also believes that the pre-set tracking is usually too generous.)
Reducing the space between letters will darken the columns of text, but increase the amount of white space that can be used more creatively elsewhere on the page. However, if you tighten the track too much, you will reduce readability.