The mold-making materials include plaster, two kinds of alginate, two forms of silicone rubber, latex, and hot-melt rubber.
Moulage is a better molding material than plaster for this job because it is flexible. A hard plaster mold would most likely break — either when you attempted to remove the original pattern, or when you tried to release the copies (also made from a hard material).
We added Plasticine, sculpting the pattern to make it look a little more like an oil lamp and a little less like a teapot. The addition of the pedestal to the finished casting will also help to convey this illusion.
Hot-melt glue (ethylene vinyl acetate or EVA) is a thermoplastic with qualities much like those of other hot melts: it becomes fluid when heated, and is ruggedly solid when it cools to room temperature. In fact, it has enough of the “right” characteristics to make it a useful casting material. We will demonstrate casting with hot glue as we construct a crown from scratch.
The filigree headband of this crown was made of a standard lamp part, called “brass banding.” The finials are twenty repeated castings of EVA (hot-melt glue).
When you can use an authentic item as a vacuum forming mold, the thin plastic casting will be very realistic. This mold is a pattern of real roofing tiles, caulked with plaster.