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What is a Font?

A font is a file containing a collection of glyphs (character renditions) sharing the following characteristics: typeface(4- 11), symbol set(D- - 7), font resolution(D- - 3), proportion and style(4- 11), and font file format(8- 5).


Typeface is the design or style that gives characters their distinctive appearance. There are thousands of English typefaces. The most well known are the serif Times Romanreg. and sans serif Helveticareg. (serifs are the tiny details at the end of a stroke(D- - 7)). Chinese examples include the hand-written brush, pen, and grass styles. Printed typefaces can simulate a brush by having hooks or dot serifs at the ends of strokes (e.g., the Ming or Mincho styles), or can be plain, sans serif (the Hei or Gothic styles).

Proportion and Style

Any particular design will have variations in proportion (condensed, normal, expanded), weight (light, normal, bold) and orientation (normal or italic). An English typeface(4- 11) specification might be Helvetica condensed bold italic.


Resolution is the number of pixels(D- - 6) or dots that make up a character's pattern. For example, the standard Chinese character screen font consists of patterns 16 pixels wide by 16 tall, or 256 pixels per character. Low resolution characters are useful because each character takes only 32 (256/8) bytes worth of storage, and displays at a reasonable size on a VGA screen. The next even font size is 24 horizontal by 24 vertical, yielding 576 pixels per character, but that font requires more than 2.5 times the storage of the low resolution font. The next typical size is a 48 point font, which is 4 times larger than the 24 point font, but prints letter quality characters at 300 dpi.

TrueTypereg.(D- - 8) fonts do not come in fixed resolutions, although they have a minimum resolution under which they do not display clearly (associated bitmap fonts(8- 5) are used instead).

Resolution and Point Size

Printed character sizes are traditionally measured in units called points (1/72 of an inch). A 12 point printed character occupies a vertical space 12/72 or 1/6 of an inch. Computer screens and printers do not use pens, brushes, or fixed metallic type to write characters. Instead, a character glyph is displayed or printed as a rectangle of dots that approximates its appearance. The number of dots in the rectangle are the measure of the resolution of the image. Character glyph resolutions are measured in dots ( pixels(D- - 6), and also points), while display and printer resolutions are measured in dots per inch (dpi). Printers have resolutions ranging from 60 to 2400 dpi. When the horizontal and vertical resolutions are equal, one number is used, but some printers have higher resolution in the horizontal direction, and two numbers are used (e.g., 240x216). Monitor resolutions are roughly 72 dpi.

Smart Characters displays or prints a character at a particular combination of point size(D- - 6) and resolution. The View | Zoom command changes image size by scaling the screen resolution value. Because the actual screen resolution is fixed, the size of the page changes to match.

Different glyph sizes are required to print the same size character at different resolutions according to the character size multiplied by the printer resolution. For example, a 12 point character (1/6 inch) occupies a 25 (150/6) pixel cell at 150 dpi. This character is perfectly rendered by a 24 point font, with one pixel row and column blank. (Blank rows are called internal leading.)

A character is rendered at its highest quality when the combination of the point size and resolution call for a glyph resolution that exactly matches an installed bitmap font(8- 5). Other resolutions are approximated by the process of bitmap scaling.

Higher Resolution Fonts

The 16 point Combined(4- 9) font works well with low resolution screen and fax displays. The 24 point font combined font yields good results when used with printers capable of 150-180 dpi resolution. Optional accessory fonts (not included) provide higher resolution printing. The 48 point font provides letter quality output on printers capable of 300 dpi.

Asian TrueType Fonts

Except for Smart Characters, Asian TrueType(D- - 8) fonts are supported only by their respective Windows operating systems: Chinese TrueType fonts don't work under Japanese Windows. The Smart Characters DoubleByte TrueType Font Interface(13- 1) supports simultaneous use of traditional and simplified(4- 10) Chinese and Japanese using any language Windows operating system.

Type Size

When metal type was used to print books, the size of the type was the same as the size of the printed image. Printed type sizes are measured in 1/72 inch points. The user's guide is printed in 11 point Times Romanreg..

Font Size

The size of an electronic font is the resolution of the font divided by the resolution of the display. For example, the Combined(4- 9) 16pt font has a resolution of 16x16. When displayed on a typical screen (conveniently 72 dots per inch), a typical character is 16/72 inches or 16 points tall. Adding the typical 2 dots of space yields the 18 point font size. When displayed on a 300 dpi laser printer, the same font is 16/300 inches or 3.8 points tall for a point size(D- - 6) of 4.3 points.

User Font

A user font contains user characters(4- 10) for a particular user. You can have any number of user fonts. The default user font is the user font installed in the active user dictionary(4- 7).

System Fonts

A system font is a specific realization of a symbol set(D- - 7) installed into Smart Characters. A system font is available to any document, and is installed and opened in one of three manners: System fonts include ideographic(4- 13) fonts and, optionally, one or more alphabetic(4- 13) fonts to form a complete symbol set(D- - 7).

Ideographic Fonts

An ideographic font is a collection of Chinese or other ideographic characters. In Smart Characters, ideographic characters display as Chars(D- - 2) objects. Ideographic fonts are typically very large, and are kept on disk and cached within Smart Characters to reduce memory requirements.

Alphabetic Fonts

Alphabetic fonts display text objects(4- 1) types other than Chars(D- - 2) (Chinese characters). The small alphabetic fonts are usually completely loaded into RAM for instant display.

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