This invention relates to labels. In one embodiment, the labels comprise a polymer facestock layer, a nano-porous layer underlying the facestock, and a metal layer overlying the facestock or underlying the facestock between the facestock and the nano-porous layer. In another embodiment, the labels also comprise a water-based adhesive in contact with the lower surface of the nano-porous layer. These labels can be bonded to substrates of glass, plastic, or metal using a water based adhesive which is in contact with the nano-porous layer.