Various embodiments herein include utilities for generating embosser drums that are used to pre-format optical media such as optical tape with a pattern of nanostructures such as wobbled grooves. One utility includes generating a plurality of replicas from an embossing master, bonding the replicas together to form a bonded replica structure having a surface with the nanostructure pattern imprinted therein, creating a replica of the bonded replica structure and electroforming a metallic layer onto the bonded replica structure replica to create a single, one piece, metallic shim which can be used to create a weld-less embosser drum.