Protected silvered substrates and mirrors containing the same

The invention provides a protected silvered substrate of the type comprising in combination, a substrate having a layer of substantially silver deposited thereon, a layer of aluminium oxide secured to the silver layer, and a layer of silicon dioxide secured to the layer of aluminium oxide, characterized by a layer of zinc sulfide between the layer of substantially silver and the layer of aluminium oxide to improve the adhesion of the alumina to the silver. The invention is particularly concerned with front surface mirrors and low emissivity glass utilizing such protected silvering.