A three-dimensional printing system includes a print bed and a shelf insertion mechanism for inserting a shelf of one or a plurality of auxiliary shelves into a print volume between the print bed and a printer head. A printer assembly is configured to deposit layers of material within the print volume to form one or more objects on a support platform, the support platform including the print bed or an auxiliary shelf that is inserted into the print volume by the shelf insertion mechanism. A controller is configured to control the shelf insertion mechanism to insert an auxiliary shelf between the print bed and a printer head of the system after formation of the objects on that support platform by the printer assembly is complete.