The University of Pennsylvania's Online Computing Magazine
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November 1991 - Volume 8:3 [Printout | Contents | Search ]
By Caroline Ferguson TrueType is a long-awaited technology for creating clear font output both on screen and from printers. Currently, the TrueType font format has been implemented for Macintosh systems only. Major font vendors have already released a substantial number of designs in TrueType format, and a basic set of TrueType fonts is included with System 7.0 software and new Apple printers such as the StyleWriter and LaserWriter LS. In the future, TrueType promises to offer consistency in font output across platforms: Support for TrueType has been announced as a feature of the forthcoming Windows 3.1. But the fanfare surrounding the release of TrueType has not been without its share of uncertainty. TrueType sounds like that free lunch you never thought you'd get - great output from cheap printers. It has users asking, "What does TrueType do for me?" and "Does it really work?"
Haven't I heard this before?TrueType's primary advantages are that you can get good screen display and good font output from low-cost printers. This functionality has been available with other Macintosh products, notably Adobe Type Manager, for several years, but TrueType claims several advantages. Because it is a part of the System software, most - and eventually all - applications will be able to take advantage of it. As a "built-in," there is no extra cost or learning curve associated with its use.
Where does TrueType fit?TrueType is a kind of hybrid, offering characteristics of the two font types that most people are familiar with - bit-mapped and PostScript - and it can be used in combination with these fonts. To better define TrueType, let's first define the other font types used on Macintoshes.
Bit-mapped fontsThe font type that most people are familiar with is bit-mapped fonts. Geneva, New York, Chicago, and Cairo are familiar examples. Bit-mapped fonts are designed to be output to the screen or printer at a specific size, like 12 or 14 points (a point is a printer's measure equivalent to 1/72 inches). The fonts reside in the system file of your Macintosh. For clear screen display and clear printed output, you must have bit-mapped fonts installed in all the point sizes you want to use. If you need to use a bit-mapped font in other than the installed sizes, your Macintosh will scale an existing bitmap to the desired size by adding or removing pixels (the dots that make up the font). The most noticeable effect of this scaling is "the jaggies" - the font will look jagged (a stair-stepped look on curved lines) or out of proportion on screen and in the printed output. Bit-mapped fonts can be used on any printer.
PostScript fontsPostScript fonts for the Macintosh, also referred to as scaleable or outline fonts, are for printed output. Times is a familiar example. For screen display, a corresponding set of bit-mapped fonts in discrete sizes, installed in the System file, give an approximation of printed output; as noted above, these bit-mapped fonts may look jagged when they are scaled. The Adobe Type Manager utility, which must be purchased separately, will scale PostScript fonts for more accurate screen display.The PostScript printer fonts consist of an outline (a mathematical description) and an algorithm to scale the outline to any point size (subject to limitations of the application and printer you are using). Printed output is consistently smooth. The font outlines are stored as separate files on your hard disk or in a PostScript printer such as a LaserWriter. The scaling is done by PostScript software and a microprocessor, both inside the printer. Since printer manufacturers must license PostScript software from its creator, Adobe Systems, and printers must have a microprocessor to do the font scaling and output, PostScript font technology is relatively expensive to implement and is not available on all printers. Dot-matrix printers, for example, do not use PostScript.
TrueType: The hybridTrueType is a hybrid font technology that has features of both bit- mapped and PostScript fonts. Like PostScript fonts, TrueType fonts are outlines, which means they do not have a fixed point size and can be scaled with minimal distortion. Like bit-mapped fonts, TrueType fonts reside in the System file of your Macintosh. The scaling to create output in the desired point size takes place in the Macintosh-no microprocessor is required inside the printer. Unlike either font technology, the same scaleable font outline is used to generate both the printer and the screen output.
TrueType on your screenSince TrueType does scaling for both the screen and printer from the same outline, what you see on screen will look more like what you get from your printer. Fonts in both small and large sizes will no longer look blocky, out of proportion, or poorly spaced on screen.
TrueType and your printerAll Apple printers and the Hewlett-Packard DeskWriter are TrueType-compatible. Inexpensive printers will show the greatest difference in output quality. A dot-matrix or ink-jet printer will provide smooth output in any point size, at the printer's highest resolution. Those who have PostScript printers will also see a difference in the output of non-Postscript fonts. If you select a regular non-PostScript bit-mapped font in a document, the printer will either substitute a PostScript font (giving clear output but often changing line breaks and character spacing) or generate a bitmap, which looks jagged. But if the non- Postscript font is a TrueType font, then your Macintosh will scale the font outline and send it to the printer, providing smooth output.
Some thorns among the rosesThese improvements may have you chomping at the bit to get TrueType capability, but as with anything, there are some caveats, ranging from the minor to the serious. The minor problems first. Although most software will eventually support TrueType, some widely used programs do not currently do so. Microsoft Word 4.0, for example, does not recognize TrueType fonts unless you have the TrueType INIT from Microsoft installed. Microsoft Word 5.0 (expected soon) will support TrueType directly.The biggest problem is a function of the way TrueType works. Since the Macintosh generates printer and screen fonts from font outlines, the speed of font generation is highly dependent on the processor inside your Macintosh - the slower the processor, the more slowly the fonts are generated. This means that TrueType is not a good choice for those with slower Macintoshes such as the Plus or the Classic. Nor is TrueType recommended for machines with less than 1 Mbyte of memory (RAM). With insufficient memory, TrueType either doesn't work at all or is too restricted to be useful.
SummaryTrueType does work. For those who want clear, readable output on both the screen and from cheaper printers, it's what you've been waiting for. For those with slower Macintoshes, it may still be a good buy if you are willing to balance improved output quality with slower print times. For those with PostScript printers, TrueType offers a greater choice of fonts.
CAROLINE FERGUSON is Front Desk Coordinator for the Computing Resource Center. Sidebar: Who's on first? One of the biggest questions about TrueType is how it will interact with bit-mapped and PostScript fonts. The listing below shows which fonts will be used when for the most commonly used printers. Some important caveats: Popular typeface designs may be offered by several vendors under different names (CG, Triumvirate, and Helvetica, for example); it is not a good idea to mix such fonts on the same line or page because, while they may look alike, they may have different character spacing, which could cause lines or characters to appear "scrunched" or "splayed." For now, TrueType compatibility and coexistence with other font types are moving targets; if you are planning to use a mixture of TrueType and PostScript fonts, check to make sure that the applications you are using can support both.
Apple ImageWriter (dot-matrix printer)
Apple StyleWriter (ink-jet printer)
Hewlett-Packard DeskWriter (ink-jet printer)
Apple LaserWriter LS (non-PostScript laser printer)
Apple LaserWriter family (PostScript printers)
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