Page full Width HowTo

Hi, I can't seem to figure out how to have content "Text etc to display full width on a page. The Full Frame option at the bottom of the page keeps resetting to default and the page layout under Theme options is set to "No SideBar Full width" but it still is not the screens full width? It appears as though there are margins or padding on the left and right side of the screen that is preventing the page from displaying full width. Thanks.