A related effect is optical alignment , which compensates for tricks of the human eye. Optical alignment adjusts each glyph's position at the beginning or end of a line of text, so the edge of the text block appears smooth and uniform. Justification is the process of stretching or shrinking a line to force it to fit a certain width. Periods and commas at the end of a line might be specified as hanging punctuation , which should be fixed outside the desired width. Line Layout uses the font's parameters under the application's overall control to ensure the best results.
Tracking is spacing adjustment which applies equally to all glyphs on a line.
Type designers can define the tracking in GX fonts to allow optimal legibility of a typeface at any point size. TrueEdit's tools for adding position effects are described in Adding Position Effects . Language and script support Throughout the world, different scripts lay out and align text in radically different ways. Reading direction can be right to left, left to right, or vertical. Some scripts depend on specific contextual forms for each glyph, while others rearrange glyphs depending on the context.