[David D]

Background images are whatever size the image is. They cannot be scaled.

If the element to which the background image is applied is smaller than the image, then the image will be cropped. If it is larger, then the image will be tiled (unless you use the background-repeat property to prevent that).

By combining multiple images you can create the illusion of an image that stretches. For example, given a div containing a heading, some content, and a footer you can assign one background image to the heading, one to the footer and one to the div itself. The header and footer images are set to not repeat, while the main div background does. This way you can have corners and top and bottom borders provided by the header and footer, while left and right edges come from the image that is tiled.

Adding a few more elements and you allow the image to scale horizontally as well as vertically.

[bitsy_]

what's the standart dimensions of an image background in webpages? and... how do I make it dynamic like if the page contains a long list downward...?