water mark effect - Page 1

i want to add water mark effect in pdf how to do this

<page backleft="10mm" backtop="10mm" backright="10mm" backbottom="10mm"
backimg="html2pdf/watermark.jpg" backimgx="center" backimgy="bottom" backimgw="100%" footer="page">
lots, and lots dynamic of contents goes here
<page_footer></page_footer>
</page>