Position effects can be applied to all glyphs in the font, or triggered by a specific context. Kerning information can be added to a GX font in several forms for flexibility. GX also allows cross-stream kerning , which moves glyphs perpendicularly to the reading direction of the text. 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 .