Microsoft KB Archive/75874

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{| The information in this article applies to:
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 * Microsoft Word for the Macintosh, versions 4.0, 5.0, 5.1, 6.0

SUMMARY
In Microsoft Word for the Macintosh, TrueType fonts may redraw, scroll, and print slower than PostScript fonts. TrueType fonts are rasterized (resized, interpreted and converted from font outlines to bitmaps) by the Font Manager, which creates bitmaps of every font from scratch. PostScript screen fonts are preinstalled for particular sizes and rasterized by the PostScript printer.

Because TrueType fonts are rasterized by the Font Manager, rather than the printer, the fonts provide crisp screen images of any point size. However, TrueType is slow to redraw the screen, especially on older Macintosh machines. PostScript bitmapped screen fonts produce screen images faster, but they are limited to displaying installed font sizes.

TrueType screen fonts are stored in a specific cache (memory space) for quicker bitmap availability. However, TrueType screen fonts and printer bitmaps compete for the same memory space when you print. The screen fonts are overwritten by the printer bitmaps. This causes scrolling to become slow after you print the document and print time to become slow after you use screen scrolling.

Because TrueType fonts are rasterized by the system, documents with TrueType fonts appear to take longer to print because the Macintosh is in use longer. Because PostScript fonts are interpreted by the printer, the computer becomes available sooner.

MORE INFORMATION
Fonts consist of outlines describing the curves and lines of a letter form. If an application requests a font's outline, the Font Manager returns a bitmap for screen display. If there is no bitmap available in the requested size, a TrueType font passes its outline information to the Font Manager's rasterizer. The TrueType rasterizer is actually three separate programs: a scaler, a hint interpreter, and a scan converter.

The TrueType rasterizer interprets detailed instructions (hints) embedded in each TrueType font. Because these three programs and each font's hints take up a significant amount of memory, some documents containing multiple TrueType fonts can be extremely slow to print or may not print at all.

PostScript fonts contain only simple hints that define the letter form and depend on intelligence built in to the PostScript interpreter located in the printer or in Adobe Type Manager (ATM).

Note: If you use ATM, the screen redraws slowly on older Macintosh machines (similar to TrueType). ATM rasterizes screen fonts with a built-in rasterizer and stores them in a memory cache. If you send a document to a PostScript printer, printer bitmaps are stored in the printer and screen bitmaps in the system. When ATM prints to a non-PostScript printer, page and screen bitmaps compete for the same memory space, causing slower scrolling and printing.
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Last reviewed: November 17, 1997

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