Horizontal rules are one of the few graphic elements you can create with HTML. Use them to separate information within an individual post or just to jazz things up a bit. Additionally, there are a few different attributes you can use to change the way your rules look.
To create a rule, you type <hr> where you want it to go. The default horizontal rule is usually thin and has shading, but you can change the thickness (height), width, shading, and color of a rule. However, not all browsers will recognize every rule attribute.
These are all the rule tags you will need to know:
<hr size="100pixels">— You can adjust the width of your rule as a fixed size in pixels, or
<hr size="80%">— You can adjust the width of your rule using the more flexible percentage (of the browser window size) measurement.
<hr height="4pixels>— You can change the height or thickness of your rule, too. The usual thickness of a rule is two pixels.
<hr noshade>— Add noshade, and you’ll just have a flat, graphic rule without the shadow.