- Only install needed fonts. Fonts take up memory and each application has to keep track of all fonts. So if you don't use it, lose it! (Classic Mac OS) former Macintosh Operating Systems Guide William Bailey
How many fonts is too many?
When you're unable to install more fonts or your fonts keep disappearing, you've probably reached the limit. A Macintosh running OS versions earlier than Mac OS 9 has a limit of 128 TrueType fonts or font suitcases in the Fonts Folder. With Mac OS 9 the maximum number of items is higher. These limits don't apply to PostScript or printer fonts or to Mac OS X.
A loose TrueType font and a font suitcase of multiple fonts each count as one item so if you have many loose fonts drag them onto a suitcase or combine suitcases to get past the item limits. Because font suitcases can hold a large number of font families you can actually have quite a large number of individual fonts. According to Apple, there are many variables so there is no absolute limit on the number of font families in a suitcase but as a practical matter they suggest a limit of about 700-1800 font families.
Memory or RAM is also a factor. There is only so much memory available for loading and keeping track of active fonts. But "too many" is more than just a limitation of the operating system. Do you really want to scroll through a huge list of fonts from within your software applications? For best performance and ease of use, you'd do well to limit active fonts to only the ones you absolutely must have and use a font manager (described below) to manage the rest.
Can I delete any fonts I don't want?
Yes and No. First, quit all applications other than the Finder before you remove any fonts in Mac OS 9. In Mac OS X shut down the Classic Environment before removing fonts. Then, before you delete a font completely make sure it's not going to be needed by other users including network users. It's usually safer to keep a copy of the font somewhere, just in case.
Although it's not absolutely necessary, the OS installed fonts are good ones to keep around. Apple provides a comprehensive list of both TrueType and bitmapped fonts included with Mac OS 7.x through 9.x.
Fonts Included with Major System Releases.
The system fonts found in /System/Library/Fonts/ of OS X should not be deleted. Additionally, Classic applications can only access fonts in the Mac OS X /System Folder/Fonts folder so don't delete or move those fonts if needed by the Classic environment. Since X apps can also use those Classic fonts even when Classic is not active, make sure you aren't using them in X applications if you plan to delete them.
But I want ALL my fonts!
Can't bear to part with your fonts but your Mac is on overload? You need a font manager. A font manager simplifies the process of activating and deactivating fonts from other folders on your hard disk and allows you to browse your entire collection - even uninstalled fonts. Some have features for printing samples, automatic font activation, or cleaning up corrupt fonts.
In addition to font browsing, programs such as Adobe Type Manager, Font Reserve, or Extensis Suitcase allow you to create font groups or sets. You can install and uninstall these font groups when you need them for a certain project. Your core or most used fonts stay installed at all times but all your other favorites are tucked away ready to be used at a moment's notice. This provides you with ready access to 1000s of fonts while keeping your system running smoothly with a manageable number of fonts in memory at any one time. If you're running OS X you'll find that some of the features found in third-party font managers are now a part of the OS, but there are limitations.
Type and Font Software Tools for Mac
Software for font management, designing type, and printing samplers under the Macintosh Operating System.