It looks so filigree and delicate, but this door mat is robust and will stand up to the rough treatment meted out by the soles of rubber boots or work shoes. The mesh is made of solid, galvanised wire. The mat can be used indoors or out, before the front door but preferably in a roofed-over area. If constantly exposed to wind and weather the zinc can begin to crumble, creating small patches of rust. But in any case, the wire mesh will colour with age and develop a dark patina.