Save the file using a ".css" extension, for instance, pagestyles.css. ... Repeat the link coding in each page of your website that you want to use the image background.

Add a short CSS class to an HTML Web page to use animated and stationary GIF images as the page's background. Open an HTML document and find the document's head section.

Google's John Mueller said this morning in a webmaster hangout at the 20:55 mark that Google Image search does not index and rank images from CSS background code. He said if you want your images ...