Image Description: This is the last step in the process. There are three steps. The first requires modelling clay as the base. It looks similar to the picture above but has the plastic pieces set in modelling clay instead of molding putty and obviously is a reverse side of the one shown above. Applying the first half of molding putty on top of the plastic pieces (no mold release required) is step 2. Then you remove the clay, clean the plastic pieces, and reinsert them into the dried half of casting putty. This looks like the picture above. Step 3 (final) is to coat the plastic and dried half of casting putty with either thin oil or mold release before putting the top half of casting putty into the mold frame. Note that I add a third level of Legos for this step. I tamp down each layer of mold putty with a square of Legos to make sure the putty gets down into all of the crevices on the plastic pieces.