From http://stackoverflow.com/questions/12170964/css-only-textured-and-stitched-ribbon

vertical-stitched-border-ribbon.html

<style type="text/css">
  .ribbon {
    background: #eee;
    border-left: 1px dashed #aaa;
    border-right: 1px dashed #aaa;
    border-radius: 5px 5px 0 0;
    box-shadow: 5px 0 0 #eee,
                -5px 0 0 #eee;
    height: 120px;
    margin: 0 5px;
    position: relative;
    width: 90px;
    -webkit-filter: drop-shadow(0 2px 5px hsla(0,0%,0%,.5));
}
.ribbon:after,
.ribbon:before {
    border-top: 15px solid #eee;
    content: '';
    height: 0;
    position: absolute;
    top: 100%;
    width: 0;
}
.ribbon:after {
    border-left: 50px solid transparent;
    right: -6px;
}
.ribbon:before {
    border-right: 50px solid transparent;
    left: -6px;
}
</style>
<div class="ribbon"></div>