Repeating css image as content

I need to have an image repeat and be visible both on the screen and while printing. So far using

body {
    background:url(images/confidential.png) repeat;
}

@media Print {
    body:before { 
         content: url(images/confidential.png);
         position: absolute;
         z-index: -1;
    }
}

works with the exception of the repeat when printing. Suggestions? Thanks.