To change the background of the viewer to an image, add the following style into HeadCSS with your desired image:
body
{
background-image: url("[URL To background image]");
}
If
you do change the background of the viewer, keep in mind you may need
to change the keyline border around the publication, as well as the
toolbar spritemap.
Please refer to the links below.
Keyline:
http://support.realviewdigital.com/solution/categories/40851/folders/65958/articles/72739-viewport-border
Spritemap:
http://support.realviewdigital.com/solution/categories/40851/folders/65958/articles/30858-changing-the-toolbar