The first step in mass hologram production is to create embossing plates called shims. A shim is made from a thin plate of metal, usually nickel, which is attached to the embossing cylinder. A ‘master’ or ‘mother’ shim is produced by an electro-deposition process whereby the plate with recombined images is immersed into a galvanic tank and metallic nickel is caused to accumulate on its surface. The mother shim is then usually used to prepare ‘daughter’ shims for the mechanical embossing process.