Working with OpenType fonts

OpenType is a cross-platform font format developed by Adobe and Microsoft that accommodates large character sets and glyphs, often including fractions, discretionary ligatures, old-style numerals, and more. When text has an OpenType font applied, you can access any style options built into that font through the Character Attributes dialog box (Style > Character).

Note: Learning about the distinction between characters and glyphs can help you understand how OpenType styles work. A character is an element of a written language — uppercase letters, lowercase letters, numerals, and punctuation are all characters. A glyph is actually an image that represents a character, possibly in different forms. For example, a standard numeral 1 is a character, whereas an old-style numeral 1 is a glyph. As another example, an “f” and an “i” next to each other are characters, whereas an “fi” ligature is a glyph.
Note: A one-to-one relationship does not always exist between characters and glyphs. In some cases, three characters (such as a 1, a virgule, and a 4) make up a single fraction glyph. Or, one character may be represented by three possible glyphs (three different ampersand symbols, for example). You can select individual characters for formatting and editing, regardless of the glyphs used.

Parent topic: Text and typography

Working with OpenType fonts