Weight: The weight of a particular font is the thickness of the character outlines relative to their height. There are many names used to describe the weight of a font in its name, differing among type foundries and designers, but their relative order is usually fixed. The terms normal, regular and plain, sometimes also book, are being used for the standard weight font of a typeface. Where both appear and differ, book is often lighter than regular, but in some typefaces it is bolder.