Abstract: A drum for a photoplotter has a base having a partially cylindrical recess formed therein which recess being defined by in part by a plurality of elevated surfaces providing a support bed on which is mounted a sheet of material providing an exposed surface for supporting a substrate thereon. The drum is formed by a method whereby a tool is provided about which the sheet material is drawn and is moved into engagement with the bed and is caused to maintain this shape by an adhesive interposed therebetween. A method for mechanically compensating for surface irregularities by fixing the scanner relative to the support surface after displacements have been made is also provided.