The PostScript page description language was developed by Adobe and became a major force when Apple adopted PostScript for its Apple LaserWriter printer in 1985. The popularity of PostScript grew over the next few years as it was adopted by many graphics programs as well as high end imagesetting devices.

To compliment the PostScript page description language Adobe developed two PostScript font formats, entitled Type 1 and Type 3. The file format specification for Type 3 was published, but due to the fact that Type 3 fonts did not render well on low resolution devices, the format never became popular. Adobe decided at that time, not to publish the Type 1 specification and it was this decision that ultimately caused Apple to develop the TrueType font format.

In 1990, Adobe finally released the Type 1 font format, but by then Apple and Microsoft had collaborated on the TrueType project and both companies were to soon release operating systems with native support for TrueType. From this point onwards TrueType was to establish itself as the font format of choice for most desktop computer users.

An Overview 

The PostScript Type 1 font format is a digital, outline font format that supports hinting. A description which can also be applied to the TrueType font format. Indeed both formats share some common attributes. Both enable any character to be scaled to any size without loss of quality and both formats support hinting, a technology which improves legibility of characters at low resolutions.

Technically, however, the font formats are quite different. Although both formats store the character outlines as mathematical definitions, TrueType uses quadratic B-splines, whereas PostScript uses cubic bézier curves. Although supporters of both formats may offer benefits of their preferred format, neither offer any real significant advantage to the user.

The other main difference, which does produce a significant advantage to the user, lies in the area of hinting. PostScript compared to TrueType has a very limited amount of control over the final displayed image. Both implementations of hinting will improve the display of characters on low resolution devices, but a well hinted TrueType font will produce significantly better images. Click here for more information regarding TrueType hinting.

The obvious question at this point must be "why do people still use PostScript fonts?". There appear to be no real benefits and indeed the reasons tend to be historically based. Firstly, because the PostScript format was established before TrueType, most type foundries have produced their fonts using the PostScript format and it is only in recent years that they have started to produce larger numbers of TrueType fonts. Therefore if a particular font is required it may not always be available in a TrueType format.

The other reason relates to imagesetting, the high end printing process used by many commercial printers. Almost all imagesetting devices use the PostScript language and historically many devices have been problematic when used with TrueType fonts. For this reason designers tend to use PostScript fonts rather than TrueType fonts to ensure compatibility with their commercial printers output devices. This problem has essentially now been resolved with new software and newer imagesetting devices and slowly the trend is changing in this area to use TrueType fonts.

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