stretch

repeat

round

initial

div#main {
    background-color:lightgrey;
    border:30px solid transparent;
    border-image: url('border.png');
    border-image-slice: 30 30 30 30;
    border-image-width: 1 1 1 1;
    border-image-outset: 0;
    border-image-repeat: stretch;
}