About semantics:
Also consider that HR has a meaning too ( loosely akin to SECTION in HTML5, VERY loosely) ,. so if this doesnt actually have a semantic meaning you could use:
IE9+ : Multiple BGs on container or last element.
OR IE8+: Apply the after in Paul’s first suggestion to the container element instead ; the container element holding the repeating brown bar image.
You really must adapt your CSS to your HTML. Think "what hooks does my markup natively provide?
here is a quickie:
<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="width=device-width">
<style type="text/css">
h3, p{margin:0;}
.article, hr {margin:2em 10% 0 10%}
.article + .article, hr{ background: url(http://www.pmob.co.uk/temp/images/brown-divider-slice.png) repeat-x 0 0; }
.article + .article h3 { background: url(http://www.pmob.co.uk/temp/images/brown-divider-small.png) no-repeat 0 0; padding-top:91px; }
/** bonus!!!**/
hr {border: none; height:61px; text-align: center}
hr:before, hr .before {content: url(http://www.pmob.co.uk/temp/images/brown-divider-small.png);}
/**for IE**/
hr {
zoom:expression(
runtimeStyle.zoom=1,
insertAdjacentHTML('beforeEnd','<span class="after"></span>')
);
}
</style>
</head>
<body>
<div class="article">
<h3>This is just an article</h2>
<p >Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
<p class="fleur">Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
</div>
<div class="article">
<h3>This is just an article</h2>
<p >Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
<p class="fleur">Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
</div>
<hr><!-- denotes a new section-->
<div class="article">
<h3>This is just an article</h2>
<p >Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
<p class="fleur">Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
</div>
</body>
</html>
hope that helps