Cascading Style Sheets manipulate the appearance of most, if not all, of the themes created for Tumblr. Web designers use Hypertext Markup Language to create the basic framework for a theme and then implement CSS to customize how each element, or object, looks on the page. To change the typeface used for the title, or header, of your blog, override the CSS in the theme using the "<p style>" tag.

Step 1

Sign in to your account and click the "Settings" icon in the top right.

Step 2

Choose a blog to edit and then click "Customize" to open the customization page.

Step 3

Click the "Edit HTML" button and then click anywhere inside the page code.

Step 4

Press "Ctrl-F" to open Find and then type "{block:IfNotHeaderImage}" (without quotation marks) into the search box.

Step 5

Press "Enter" to locate the term in the page documentation. The entire tag should be white in color. If "block" is colored blue, you're viewing the wrong section of the code; continue pressing "Enter" until you find the correct tag.

Step 6

Locate the "{Title}" tag, positioned between the "{block:IfNotHeaderImage}" and "{/block:IfNotHeaderImage}" tags.

Step 7

Encase "{Title}" in the "<p style>" and "</p>" tags, like so:

<p style>{Title}</p>

Step 8

Attach the "font-family" property to the "<p style>" tag to define the typeface for the blog title. Your code should look identical to the following:

<p style="font-family: '[font]';">{Title}</p>

Replace "[font]" with the exact name of the preferred typeface, such as "Courier New" or "Times New Roman."

Step 9

Click "Save" to commit your changes, and then click "Close" to return to your dashboard.