What's the Difference between TrueType, PostScript, and Bitmap Fonts?:

Because the Macintosh screen has a resolution of 72 dpi, and the ImageWriter printer (the standard when the Macintosh was introduced) had a resolution of 144 dpi, a Mac printing a 12 point bitmap font to an imagewriter displayed the 12 point bitmap font on screen, and sent the 24 point bitmap to the printer, which shrunk the font to 12 points and printed it at 144 dpi. While this process resulted in true WYSIWYG printing, good results could only be acheived by using fonts and fonts sizes for which you had a font size twice as big, otherwise printouts (and the screen display) would be jaggy.

With the introduction of PostScript and the LaserWriter, printing technology changed dramatically. PostScript fonts are not stored as bitmaps, but as mathmatical outlines of each character. This allows PostScript fonts to be printed at any size without the "jaggies". Unfortuneatly, there was no way to display font outlines on the Macintosh screen (yet), and bitmap fonts were still needed. In order to accomodate the new technology, the Macintosh began to use "font substitution". Bitmapped characters on the screen were not printed as they were displayed, but the characters they represented were sent to the LaserWriter, which printed them out using PostScript fonts stored in it's ROMs. The city-named fonts on the screen were substituded with PostScript fonts. Bitmaps of the PostScript fonts stored in the LaserWriter were used onscreen to keep the desktop publishing WYSIWYG. There were several bitmaps for each PostScript font, one for each of the commonly-used point sizes. The screen display still suffered from the "jaggies" with large type, however. New PostScript fonts were sold; one file containing the PostScript outline font (stored in the System folder), and several bitmapped versions of the font at common point sizes. These additional outline fonts not built into the LaserPrinter's ROMS were sent to the printer along with the text when the Macintosh printed; the bitmapps were only used onscreen. The 300dpi resolution of the LaserWriter, combined with the PostScript font outline technology, vastly improved the final output.

Adobe Type Manager (ATM) changed the Macintosh printing world again by allowing the Macintosh to display font outlines on screen. PostScript fonts could be resized to any value, and the screen display showed no "jaggies". At small point sizes most common to publication, the mathmatically-defined outline fonts did not look as good as the bitmapped fonts drawn previously. If a font was displayed in a size for which there was a bitmapped font, ATM used the font bitmap (because it assumed that the bitmap would look better than the outline). If the size was non-standard, ATM drew the font using the Postscript outlines.

After a while, Apple and Microsoft decided that Adobe's Postscript controlled too much of the Desktop Publishing market, and they developed TrueType; a similar font-outline technology. Like PostScript fonts, Truetype fonts have both a font outline file and a set of font bitmaps at common point sizes. The primary difference between the two is that Poscript is a complete page-description format, and can be used to generate graphics as well as text. TrueType is limited to fonts. TruType's penetration into the desktop publishing market is due primarily to its inclusion in both the MacOS and Windows operating systems, but PostSscript is still the standard among professional desktop publishers.

Installing a TrueType Font:

• Suitcases are collections of fonts. A single suitcase file can contain any number of related or unrelated font files. The "Fonts" folder can only contain 128 items, but by using suitcases, the Macintosh can use an unlimited number of bitmap or TrueType fonts.
• Bitmapped fonts (also referred to as "screen fonts") can exist as single files, or they can be grouped together into a suitcase. Each file contains a single pixel-by-pixel representation of a font at a given size. It is usually better to keep all of the bitmap fonts for a given font together in one suitcase.
• TrueType fonts contain the font outlines. They do not require font bitmaps; if there is not a bitmap for the current font size, the Macintosh will generate the characters from the font outline stored in the TruType file. It is usually bette to keep the TrueType file together with it associated bitmaps in one suitcase.

1. Organize the font files into suitcases
2. Drag the suitcases onto the system folder and tell the Macintosh it is okay to place them in the appropriate place, or drag them directly into the "Fonts" folder within the System folder.

• Suitcases are collections of fonts. A single suitcase file can contain any number of related or unrelated bitmap files, but it cannot contain any PostScript outline files. The "Fonts" folder can only contain 128 items, by using suitcases, the Macintosh can up to 127 PostScript fonts.
• Bitmapped fonts (also referred to as "screen fonts") can exist as single files, or they can be grouped together into a suitcase. Each file contains a single pixel-by-pixel representation of a font at a given size. It is usually better to keep all of the bitmap fonts for a given font together in one suitcase.
• PostScript fonts contain the font outlines. They do not require font bitmaps; if there is not a bitmap for the current font size, the Macintosh will generate the characters from the font outline stored in the PostScript file. The PostScript file belongs in the Fonts folder with its associated bitmaps.

1. Install Adobe Type Manager (ATM) and restart the Macintosh
2. Organize the font bitmaps into suitcases for any additional PostScript fonts
3. Drag these suitcases onto the system folder and tell the Macintosh it is okay to place them in the appropriate place, or drag them directly into the "Fonts" folder within the System folder
4. Drag any additional PostScript files into the Fonts folder within the System folder and restart the computer

System 6:

System 6.0.8 and earlier required an application called, "Font/DA Mover" to install and remove fonts from the System file. Postscript fonts were store directly within the System folder. Under System 6 and earlier, bitmap and TueType fonts could not exist outside of suitcase files.