In this research paper a new methodology for 3D Printing concrete onto a temporary freeform surface is presented. One of the geometrical restrictions associated with printed paste materials such as concrete is that material must be self-supporting during printing. The paper explores the possibilities of printing on top of a temporary freeform surface in order to overcome this restriction. This is achieved by combining a flexible-mould developed at TU Delft with a 3-axis gantry printer provided at TU Eindhoven. A number of hypothetical cases are studied, namely fully-printing geometries or combining 3D printing with casting concrete. The final outcome is a 5m2 partially-printed and partially-cast shell structure, realized through a completely digital workflow using Grasshopper and Rhinoceros