A molding process for forming a three-dimensional article in layers. In one embodiment, a matrix comprising a planar grid-like member having a plurality of openings formed therethrough is employed. In an initial layer, casting material and mold material are deposited in selected openings to form a portion of the article in that layer with the casting material surrounded by the mold material. The matrix is located sequentially in adjacent layers and in each layer, the selective deposition of casting and mold material is repeated whereby the article is formed layer by layer from the casting material held in place by the mold material. The casting material is solidified and the mold material is removed.
In another embodiment, planar layers of material are sequentially deposited. In each layer, prior to the deposition of the next layer, a portion of its area is solidified to define that portion of the article in that layer. Selective solidification of each layer may be accomplished by using heat and a selected mask or by using a controlled heat scanning process.