3.2 Font Metrics

Once loaded, a font contains a number of general properties described below. Each property is stored in a slot which may be accessed with the corresponding reader.

• design-size is the font’s design size, in TeX point units. For example, the design size of cmr10 (the Computer Modern 10pt font) is 10. Apart from the slant (see below), all other dimensions are given in design size units (not TeX point units!).
• The slant of the font is a scalar ratio.
• The font’s normal interword “glue” is provided by three separate values: interword-space, interword-stretch, and interword-shrink.
• TeX’s usual font-dependent units are provided as em and ex.
• Finally, the font’s additional space to put at the end of sentences is available as extra-space.