Abstract: A copier receives different documents on two platens, one of which preferably has a recirculating feeder associated with it for sequentially feeding a plurality of sheets from one document to the platen for copying each sheet in a known manner. The first platen is used to make most of the copies from the copier and is used to keep the machine running substantially continuously. The other platen can receive another original document including, for example, a document that is too large to be accommodated on the first platen or by the recirculating feeder, a document that will not feed reliably through the feeder (such as a document made by assembling copy onto a backing sheet) and a single sheet document. Thus the second platen can be used for making document masters that are then placed in the recirculating feeder on the first platen.