Cascading Style Sheets: The Definitive Guide, Second Edition

Font Weights

Even though you may not realize it, you’re already familiar with font weights; boldfaced text is a very common example of an increased font weight. CSS gives you more control over weights, at least in theory, with the property font-weight.

font-weight

Values

normal | bold | bolder | lighter | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900 | inherit

Initial value

normal

Applies to

all elements

Inherited

yes

Computed value

one of the numeric values (100, etc.), or one of the numeric values plus one of the relative values (bolder or lighter)

Generally speaking, the heavier a font weight becomes, the darker and “more bold” a font appears. There are a great many ways to label a heavy font face. For example, the font family known as Zurich has a number of variants, such as Zurich Bold, Zurich Black, Zurich UltraBlack, Zurich Light, and Zurich Regular. Each of these uses the same basic font, but each has a different weight.

So let’s say that you want to use Zurich for a document, but you’d like to make use of all those different heaviness levels. You could refer to them directly through the font-family property, but you really shouldn’t have to do that. Besides, it’s no fun having to write a style sheet such as this:

h1 {font-family: 'Zurich UltraBlack', sans-serif;}
h2 {font-family: 'Zurich Black', sans-serif;}
h3 {font-family: 'Zurich Bold', sans-serif;}
h4, p {font-family: Zurich, sans-serif;}
small {font-family: 'Zurich Light', sans-serif;}

Aside from the obvious tedium ...