RISO SF Master Roll refers to the consumable “master paper roll” used in RISO SF digital duplicator machines (a type of high‐speed, low‐cost duplicator/print system). RISO machines don’t print like normal printers — they first cut and expose a master (a stencil) onto a roll, and then use that master to transfer ink onto paper. The master roll is the roll of master paper that gets processed to create the stencil used for printing multiple copies