A method of fabricating a three dimensional model from a composite model formed by a plurality of layers. The composite model comprises at least one shell material encasing and enclosing a build material. The method comprises the steps of (1) depositing a build layer of the build material onto a preceding layer, (2) removing a selected area of the build material from the deposited build layer; (3) depositing the shell material in any removed selected area of the build material; and (4) reducing the build layer to a desired final thickness for supporting a next build layer. Then repeatedly repeating steps (1) through (4) for each build layer until the composite model is completed. Finally, the undesired extraneous material, and possibly the shell, are removed to obtain the final model.