Okay, tracking and kerning are a weird sort of creature. The units express a percentage of the em space (the width of the letter M which is generally a fairly wide letterform) for that font. This varies from font to font, of course. Kerning is for adjusting the width for specific letter pairs and tracking is the same, but expressed for the entire line or selection of text with that font. So, if you track 80% down, you are reducing your normal amount of zero to -80 (-100 would be a full em space). Depending on your font, though, this may jumble up some of the letters. Also, be sure you aren’t just condensing the type horizontally (the “T” over the left-to-right arrows) which would be 20% of the normal width (this is a stretch and has nothing to do with kerning or tracking). Finally, if you track to -80, you may need to go back to individual letter pairs and re-kern so the type is legible and readable.
Post results if you can. What font are you using?
Save early. Save often.
Jonathan Ziegler
http://www.electrictiger.com
520-360-8293