An apparatus and method for the production of substitute skin that advantageously reduces the amount of donor dermal cells needed from non-wound areas of a patient having a wound to be auto-grafted is reduced by using all of the harvested skin cells. A 3D printer is used to construct a wound graft product from the harvested skin cells without wasting any of the harvested skin cells. In a case of an irregularly shaped wound, wastage of harvested skin associated with trimming is avoided.
