Abstract: A method of converting a master processing apparatus for performing a master processing operation wherein adhesive bonding is affected between a pair of stock materials and a master received therebetween from a first configuration configured for use with a pair of individual removable feed rolls to a second configuration configured for use with a cartridge including a cartridge body and a pair of feed rolls rotatably mounted on the cartridge body. The apparatus in at least its first configuration includes a frame and a master processing assembly. The method includes mounting a cartridge support assembly to the frame, the cartridge support assembly being constructed to support the cartridge in an operative position wherein the stock materials on the feed rolls of the cartridge can be fed into the master processing assembly for performance of the master processing operation.