Board Thread:Support Requests - Designing Your Wikia/@comment-4958180-20141009022658/@comment-14310002-20141009031047

It would need to be exactly big enough to fit the whole page. And then, like Carnage said, you would click it to "fixed". You can follow my background (http://img1.wikia.nocookie.net/__cb20140921144746/wicked/images/8/8a/Wiki-background.jpga) for a general template.