A method for fabricating a three dimensional model, the method comprising the steps of: fabricating a composite model on a layer by layer basis, each layer including a model material forming the three dimensional model and a sacrificial mold material forming a sacrificial mold for the model material, the three dimensional model including a void, wherein each successive layer is formed by the steps of: a) depositing at least one line of a sacrificial mold material delineating at least one boundary of the model within the layer by a drop-by-drop deposition, b) in each layer having a region included in the void, depositing lines of sacrificial mold material in a grid pattern delineating the region of the layer included in the void, by drop by drop deposition, whereby the grid patterns in successive layers having regions in the void, forming partitions of sacrificial mold material that form filler spaces for receiving the model material to form filler elements of model material separated by the sacrificial mold material partitions occupying the void; c) depositing the model material onto regions of the layer delineated by the at least one boundary of the model and in the filler spaces defined by the grid pattern delineating the region of the layer included in the void, at a rate faster than a rate at which the sacrificial mold material is deposited; d) removing a thickness of the sacrificial mold material and the model material to reduce the fabricated layer to a selected thickness of the sacrificial mold material and the model material; e) repeating steps (a) through (d) until the composite model is completed; and f) removing the sacrificial mold material from the composite model to separate the three dimensional model. from the composite model, by a process effecting only the sacrificial support material; whereby, upon removal of the sacrificial mold material from the composite model, said filler elements of model material filling the void will be released from the three-dimensional model thereby to form the void in the three-dimensional model. fabricating a composite model on a layer by layer basis, each layer including a model material forming the three dimensional model and a sacrificial mold material forming a sacrificial mold for the model material, the three dimensional model including a void, wherein each successive layer is formed by the steps of: a) depositing at least one line of a sacrificial mold material delineating at least one boundary of the model within the layer by a drop-by-drop deposition, b) in each layer having a region included in the void, depositing lines of sacrificial mold material in a grid pattern delineating the region of the layer included in the void, by drop by drop deposition, whereby the grid patterns in successive layers having regions in the void, forming partitions of sacrificial mold material that form filler spaces for receiving the model material to form filler elements of model material separated by the sacrificial mold material partitions occupying the void; c) depositing the model material onto regions of the layer delineated by the at least one boundary of the model and in the filler spaces defined by the grid pattern delineating the region of the layer included in the void, at a rate faster than a rate at which the sacrificial mold material is deposited; d) removing a thickness of the sacrificial mold material and the model material to reduce the fabricated layer to a selected thickness of the sacrificial mold material and the model material; e) repeating steps (a) through (d) until the composite model is completed; and f) removing the sacrificial mold material from the composite model to separate the three dimensional model. from the composite model, by a process effecting only the sacrificial support material; a) depositing at least one line of a sacrificial mold material delineating at least one boundary of the model within the layer by a drop-by-drop deposition, b) in each layer having a region included in the void, depositing lines of sacrificial mold material in a grid pattern delineating the region of the layer included in the void, by drop by drop deposition, whereby the grid patterns in successive layers having regions in the void, forming partitions of sacrificial mold material that form filler spaces for receiving the model material to form filler elements of model material separated by the sacrificial mold material partitions occupying the void; c) depositing the model material onto regions of the layer delineated by the at least one boundary of the model and in the filler spaces defined by the grid pattern delineating the region of the layer included in the void, at a rate faster than a rate at which the sacrificial mold material is deposited; d) removing a thickness of the sacrificial mold material and the model material to reduce the fabricated layer to a selected thickness of the sacrificial mold material and the model material; e) repeating steps (a) through (d) until the composite model is completed; and f) removing the sacrificial mold material from the composite model to separate the three dimensional model. from the composite model, by a process effecting only the sacrificial support material; whereby, upon removal of the sacrificial mold material from the composite model, said filler elements of model material filling the void will be released from the three-dimensional model thereby to form the void in the three-dimensional model.