body
{
background-image:url('http://3.bp.blogspot.com/-bLAcf0Nfeg8/Urke9Ju2MJI/AAAAAAAAAr8/cGOBarSELKQ/s1600/gradient1.png');
background-repeat:repeat-x;
}
<body>
<h1>Hello World!</h1>
<p>If the image is repeated only horizontally (repeat-x), the background will look better:</p>
</body>