Mussels have an iridescent lustre and the glass surface of this relief is cut in lines to echo how this nacre is formed, in layers and ridges. Light bounces from these tiny ridges, appearing to the eye as mother of pearl, or a spectrum of colour. This panel image represents a closeup view of the same mussel-encrusted tree. It considers how, when observed from a distance, the surface looks deceptively rounded – soft, even – but close up it is made of razor-sharp edges.