TrueType is a popular font technology which is supported by all major operating systems. Until a few years ago those systems actually shipped with numerous TrueType fonts. Nowadays the OpenType font format has taken over but there are still millions of TrueType fonts and users around.
This font format was originally developed by Apple Computer in the late 80’s. In theory, TrueType fonts are cross platform fonts but in reality, there are differences in the way TrueType fonts are handled on Macs and Windows systems.
TrueType fonts are outline fonts which means that they can deliver output at any resolution or size. In TrueType fonts, the character shapes are defined using quadratic B-splines curves. These curves are a variation on the cubic Bézier curves that are used in PostScript. Potentially this means that characters can be defined using less points that needed in PostScript fonts (a circle takes twelve points in PostScript versus eight in TrueType). But this is not always the case and it also doesn’t necessarily mean that TrueType fonts are processed any faster by RIPs. Any quadratic spline can be converted to a cubic spline with essentially no loss. A cubic spline can be converted to a quadratic with arbitrary precision, but there will be a slight loss of accuracy in most cases. This means it is easy to convert TrueType outlines to PostScript outlines, harder to convert PostScript to TrueType.
The TrueType font technology offers very sophisticated control over hinting, a technique used to improve the output quality of fonts on low resolution devices or small point sizes. Although the TrueType technology is superior to PostScript fonts in this regard, it does not necessarily mean that all TrueType fonts provide superior output quality compared to PostScript Type 1 fonts. Much depends on the effort the font designer put into the design. Don’t expect cheap 1000-for-9.95$ fonts to actually utilise much of what is technically feasible.
Another unique feature of TrueType is its support for licensing restrictions. Every font manufacturer can embed data in the font that document whether it is allowed to print using that font or to embed it in PostScript files. Until Acrobat 4, there wasn’t any software on the market that respected these flags. Click here for more information on this issue.