In OS X versions prior to 10.5, if you wanted to preview a font, you had only a couple of choices: you could view it in Font Book, or in an application that supported some form of font previews. In Leopard, though, there are at least three new ways to preview fonts. If you just want a quick idea of what your fonts look like, just open a fonts folder (your user’s is in your Library/Fonts folder; the all-user fonts are in the top-level Library/Fonts folder, and the system fonts are in /System/Library/Fonts) in the Finder. In list and column view mode, you’ll see a very small preview icon of the font, showing the letters “Ag” in each font’s face. Switch to icon view, and you’ll get a somewhat larger version. Switch to Cover Flow view, and you’ll get a flippable view of those same preview icons.
The best way to preview fonts in 10.5, though, is with Quick Look. Select a font file in the Finder, then press the Space Bar. Instead of seeing a huge version of the “Ag” icon, you’ll see uppercase and lowercase versions of the alphabet, along with the digits 0 through 9. This makes it simple to get a quick glance at a font.
But what if you really want to take a close look at that font? It turns out that the Quick Look PDF zoom keys also work when previewing a font. So just press Command-Equals a few times, and you’ll be looking at a really close-up view of your selected font. (Zoom back out with Command-Minus when you’re done.) If this doesn’t seem to work for you, make sure the Quick Look window is active first—clicking on it is the easiest way to do that. As with the PDF zoom, you can zoom in or out much more than you would ever practically find useful.
Note that when testing this hint, I occasionally had a problem where the previews wouldn’t show in Quick Look, especially on my large top-level Library/Fonts folder—instead of the alphabet, I’d simply see the font’s actual icon. In those cases, simply leaving the folder active in the Finder seemed to fix the problem—I think this is because the Finder has to generate the previews first, before you can use Quick Look on them.