When text is drawn, the operating system aligns each character by positioning its character cell next to that of the previous character.

A monospace font provides the same amount of space for each character, whatever its shape. These fonts also are called fixed fonts. Courier and System Monospaced are monospace fonts. Monospace fonts, in fact, are essential for some purposes- for example program listings, where vertical alignment is important.

A proportionally-spaced font is one in which some characters are allotted less space than others, so that each character occupies the proportion of space that is correct for its shape. For example, a lowercase letter l does not need the same space as a lowercase letter m. Many graphics fonts supplied by the PM, including the system font, support proportional spacing.

The font metrics value maxcharinc specifies the width of the widest character in the font, and the value avecharwidth specifies an average width of the characters in the font.

You can retrieve information about the widths of the characters in the current font by calling GpiQueryWidthTable. You provide the code point of the first character you are interested in and the number of characters for which you want width-table information.