For flat pieces such as buckles, pins, and pendants, we recommend vulcanized silicone rubber. It is a firmer rubber and has a very smooth surface, which makes for a smoother injected wax pattern. For more convoluted pieces such as fashion rings, complex bracelets, and any piece that has serious draft or undercuts, we use a latex based rubber that is more flexible while still having good memory. This means that the mold will fit together properly and allow the injected wax pattern to be removed without breaking it.
Molds made from wax, organic, or large patterns
Since the heat required for the above type of molds will damage wax or organic patterns, we would use a liquid room temperature vulcanized (RTV) silicone rubber mold. We would also select this type of mold for very large pieces. It is a more labor intensive process, requiring the use of a vacuum chamber and if necessary, the fabrication of a custom built mold frame.
Mold making lead time
Usually 1 week for vulcanized latex and silicone molds and a little longer for silicone RTV
Cost to make molds
Mold cost begins at $35 for a small mold made of either latex or vulcanized silicone rubber and go up in price depending on size. RTV molds start at $50.