Creating a completely custom Tumblr layout can be a lot of work, and isn't necessary to make your blog stand out from the crowd. In fact, one of Tumblr's many default themes could suit your blog just fine, provided you make a few simple changes to help it look unique. You can, for instance, set the blog's background image to show only once instead of repeating endlessly, letting the background color show through on the rest of the page.

Step 1

Log in to your Tumblr account and click the "Settings" button on your dashboard. If the blog for which you want to modify the background isn't your primary one, select it from the list on the settings page.

Step 2

Click "Edit Theme" to open the theme options list. Scroll to the very bottom of the list and then click "Advanced Options."

Step 3

Type or paste the following code in the text field labeled "Add Custom CSS":

body { background: no-repeat; }

If the theme you're using has no background image, and you want to both add one and set it to not repeat, type or paste the following code instead, replacing "IMAGE_URL" with the address of the image you want to use:

body { background: url('IMAGE_URL') no-repeat; }

Step 4

Click "Save" and then click the arrow to return to the theme options list. From there, click "Exit" to return to the settings page and then click the "Home" button to return to the dashboard.