Este es el archivo footer.php
<?php
/**
* The template for displaying the footer.
*
* Contains footer content and the closing of the
* #main and #page div elements.
*
* @package WordPress
* @subpackage Twenty_Twelve
* @since Twenty Twelve 1.0
*/
?>
</div><!-- #main .wrapper -->
<footer id="colophon" role="contentinfo">
<br />
<br />
<div class="site-info">
credits
</div><!-- .site-info -->
</footer><!-- #colophon -->
</div><!-- #page -->
<?php wp_footer(); ?>
</body>
</html>
Y esta la parte del CSS:
/* Footer */
footer[role="contentinfo"] {
background: url(
http://pelusasfactory.net/images/background-footer.png) repeat-x;
text-align:center;
left: 0;
bottom: 0;
width: 100%;
height: 155px;
position:absolute;
}