A starter piece for printing a three-dimensional item includes a main body having a face surface, a keel coupled to the main body, a guide tab extending from the keel, and at least one retaining mechanism coupled to the main body. Printing a three-dimensional item with an additive manufacturing system having a print foundation, a print head configured to print the three-dimensional item, and a plurality of support rails includes printing a support structure for the three-dimensional item in a layer by layer manner along the printing axis along with the printing of the three-dimensional item. The support structure is printed to provide a support between the three-dimensional item and the plurality of support rails of the additive manufacturing system.