Cuttlefish bone casting is a form of gravity casting and was used thousands of years ago by the Chinese and the Greeks, among other peoples. Logically the method was developed in geographical areas that were near the sea or ocean and therefore had access to cuttlefish bone. Landlocked areas used clay, sand or tuff stone for gravity casting. Gravity casting is still widely used throughout the world today.
I studied with Maestro Baiocco who had worked for Bulgari making signet rings. Bulgari used lead and indio models with no undercuts to impress the design into the cuttlefish bone. Maestro Baiocco produced one signet ring from scratch every day. Actually he produced it in 4 hours, went off to the horse races and came back to the lab shortly before closing time to give the ring it’s final polish. The procedure is: make the mold, cast, file inside of ring smooth, place on steel ring mandrel and use steel hammer to compact the metal, file inside to final ring size, file outside to desired shape, hollow out the form and finish. This technique can be instant gratification and is useful for producing that one missing part for an object that is in consignment today.
The Maestro’s tips: 1. Place a thin curved strip of zinc across the sprue opening. The hot metal will instantly melt the zinc and the flow will be quicker and smoother. 2. Never cast on a cloudy day. The additional atmospheric moisture causes more vapor release and therefore more porosity in the metal.
I do agree with Mr. Hall when he says that “it can be a very temperamental material to work in”. It is difficult to get repeatable results. And the weight of the casting is up to the gods. But seeing as how the cuttlefish bone texture remains quite popular as a surface texture I, and many others, cheat a bit to get controllable results.
Very simply one does a few carefully prepared castings of desired shapes and then makes a rubber mould of them.
These wax pieces have the cuttlefish bone pattern on both sides and can be used for bracelets, necklaces and earrings. The long, narrow, half round wax wire I generally use as the central part of weddings bands with smooth lateral borders. I have used these elements, on client’s request, to make many jewelry items.
This custom order is just hot off of my work bench and you can see more photos here. The client specifically asked that the bracelet base have the cuttlefish bone texture. The bracelet is 7 1/2 in (19 cm) long, 1 in (2.5 cm) wide and weighs 77 grams. My estimate as to how much gold would be required to make the bracelet was 71 grams and was calculated using 1 mm as the average thickness. This meant that the textured base needed to be 0.8 mm thick or less. Also the inside of the bracelet was to be smooth.
Here is how to do it. File and sand flat 2 or 3 cuttlefish bones. With a soft brush eliminate the powder from the bones veining. Dust talcum powder onto both sides of a 1 mm sheet of pliable wax and place the wax on the cuttlefish bone.
Using disposable thin latex gloves to avoid leaving fingerprints, press the wax into the cuttlefish bone design. Press firmly and in small areas with your thumbs to get a good impression on the wax. Gently remove wax sheet from bone and cut out the shapes and sizes needed.
So I always have cuttlefish bone in my lab, whether it be for a quick cast or to rob nature’s design.