Add wallpaper or a background image
You can add a small, tiled image to the background of a page body or border to give your Web pages texture. Or, you can use a single, larger image as a page background.
To add wallpaper or a background image
Place the cursor in the page area where you want the wallpaper or background to appear.
Right-click and choose Properties > Page Area.
On the Background tab, select Image and then Browse to the folder that contains your images. Click a picture to preview it. (For help with wallpaper, see below.)
Click Open.
Adjust the alignment and tiling options. Whether or not you choose scroll image with text, the behavior of scrolling text varies among different Web browsers.
Click OK or Apply to see the image in the background.
All About Web Site Wallpaper
Many Web sites use "wallpaper" to give texture to their Web pages. To do this, they add small images that "tile," repeating them over and over for an attractive pattern or texture. Use this procedure to add wallpaper to your site.
Many sites have "free" or non-copyrighted images that are designed to work well as wallpaper. Small PNG and JPG files are best. When you have found one you like on the Web, right-click and save it to your local drive, then remember its name and location so you can include it in your Web site file.
If you want the same wallpaper on every page, choose Tools > Page Layout Editor and add the background image to the page layout. When you click Finished it will appear on every page that uses the current page layout.
A large image can also be used as wallpaper; to keep your site readable, use one that contrasts with your text. For example, if your site uses black text, make sure your photo is light enough to let the text stand out.
If you use an animated PNG image as a background or wallpaper image, the image will not be animated when you published the Web site.
More detail: