The font size is typically measured in points (72pt = 1 inch). A 6 pt font is the famous "fine print" in contracts, while a 24 point font might be used for major headings. 10 to 12 pt is typical for normal print.

Some TopLeaf values (such as interword space) are measured in terms of the point size. Printers often refer to this value as an em, since it corresponds to the width of an M character in most fonts. Standard characters such as U+2003 (EM SPACE) and U+2014 (EM DASH) depend directly on the font size.

The default size is {inherit} which means to keep using the size inherited from the parent.

The size can be set using the resolved value of an attribute variable or user variable as described in “Using variables”.