Black weave, based on http://lea.verou.me/css3patterns/#chocolate-weave

weave.css

background: linear-gradient(45deg, #222 12%, transparent 0, transparent 88%, #222 0),
    linear-gradient(135deg, transparent 37%, #111 0, #444 32%, #111 63%, transparent 0),
    linear-gradient(45deg, transparent 37%, #222 0, #222 63%, transparent 0) #000;
    background-size: 15px 15px;