a substrate manager for a substrate exposure machine is used , in one example , as a platesetter . as such , it comprises a substrate storage system , containing one or more stacks of substrates , such as plates in one implementation . a substrate picker is provided for picking substrates from the stack of substrates . the substrates are then handed to a transfer system that conveys the substrates to an imaging engine . according to the invention , a substrate inverter system is also provided . this system inverts the substrates from being imaging or emulsion side down to emulsion side up in the present implementation . this allows plates , for example , which are stored emulsion side down in cassettes to be flipped to an emulsion side up orientation , and then transferred , using the substrate transfer system to the imaging engine . this flipping process has two advantages . first , the plates can be emulsion side up during the transfer . this prevents any damage to the sensitive plate emulsions . moreover , the plates , now in an emulsion side up configuration are in the right orientation for being installed on the outside of a drum on an external drum imaging system , as is common in many platesetters . also , the plates are picked from the non emulsion side . thus the system is less sensitive to emulsion formulation changes . a slip sheet capture mechanism is also provided to pass slip sheets separating the plates to a storage location .