Final Cut Pro's Text generators use TrueType fonts only. The Text generators include all the versions of the tools located in the Text submenu, which you access by clicking the Generator button in the lower-right corner of the Viewer. Most professionally generated fonts come in both TrueType and PostScript fonts. When you add fonts to your Macintosh, only the TrueType format works from within Final Cut Pro's Text generators.
It's a good idea to pick fonts that are not too thin or small. Because video is interlaced, one-pixel lines tend to flicker, so you achieve better results using larger font sizes. The smaller sizes look better with sans serif fonts such as Arial and Helvetica. Many editors tend to stay away from scrolling or serif-type fonts, but if they are large enough, they can work quite well.
The Calligraphy tools supplied by Boris FX in FCP 4 can use both TrueType and PostScript fonts. These tools include Title 3D and Title Crawl. They also can be found on the Generator button's pop-up menu.
To install fonts that can be used in Final Cut Pro, place them in the System>Library>Fonts folder. Where they can be used, they appear in the titler 's font list. You can also put them in the folder User >Library>Fonts for use by individual users.