Tortoise Shell Casting

Our Explore the Wild exhibit area has wonderful native and exotic animals to take in and enjoy. At each location we have “interactives” for people to get up-close with. It might be scat at bears or fur at wolves and bird calls at the Wetland Overlook. Each item helps people to connect with the animals and build a relationship with something one cannot touch, or sometimes even see.

We’ve been trying to get a tortoise shell at Lemur/Tortoise Overlook since before the tortoises arrived 1.5 years ago. Acquiring an endangered species shell is a challenge, replicas of other tortoise shells wouldn’t work for us, and our first pass at making our own reproduction failed. We wanted a scientifically accurate reproduction of a radiated tortoise shell, and after much research were unable to find a satisfactory reproduction.

radiated tortoise, #12, as she’s known.

We began to research doing a live cast. We came up with a product deemed safe for the tortoise and a team experienced in working with it. We talked with Scenic Artistry about doing this live cast, and they were happy to work with us. They recommended using Body DoubleTM Silk, a rubber molding material that’s safe to use on skin.

Having a safe product and experienced team was only half the task. We now needed to make sure the tortoises themselves would be as safe and stress-free as possible during the casting process. Just because the product is used on human faces and bellies doesn’t mean a tortoise will do well with the process.

So, the Keepers picked the tortoise they thought would handle the casting well– one fairly easy-going and interested in engaging with us (and food). Then we did a test run. We set up the people, equipment, product, and for about 5-15 minutes put the material on one tortoise scute. The tortoise seemed fine, not reacting to the product on its shell nor the noise of work, ate lettuce and strawberries, looked for more when finished, and returned to her home with the rest of the tortoises without apparent issue.

Brianne Ellis of Scenic Artistry applying the first coat on tortoise #12

With the test run successful, we felt we could move forward with the complete casting. Why do we go through so much trouble? One of the goals of the museum is to have scientifically accurate exhibits that are also accessible to different learning styles. Visitors aren’t able to touch the real tortoises, but a realistic model may help visitors connect with the endangered radiated tortoise and notice details in a new way.

So, last week we undertook the casting! We worked with Jeff and Brianne Ellis of Scenic Artistry to make a mold of a radiated tortoise shell. The mold will allow the creation of a reproduction, or cast, of the tortoise’s shell for visitors to touch and examine up-close. (Jeff and Brianne are talented artists and sculptors who repaired and repainted our dinosaur models earlier this year).

# 12 chowing down on strawberries atop romaine lettuce plates as layer one of the casting material sets.
Keeper Janine, left, worked with Jennifer from our Exhibits department and Brianne. It was a team effort. The plaster strips were the last item to add.

Brianne mixed and carefully spread a thin layer of Body Double Silk on the shell of “Number 12” tortoise, avoiding her head, legs, and tail. Keeper Janine gave the tortoise fresh strawberries and lettuce during the process. When the first layer was set, Brianne added a second layer to reinforce the mold. Then we added a layer of plaster strips to create the “mother mold,” the rigid outer shell that protects the rubber mold. After about one hour, we removed the plaster mold and peeled off the rubber mold.

#12 wandered around while the plaster dried. Keeper Janine walked with her, keeping a soft towel between the tortoise and anything she might bump into.
Jeff removed the “mother mold” so the cast could securely be packed in it upon removal
can you notice the grooves and pattern in the cast?

Brianne and Jeff took the mold back to their studio in Maryland and will make the cast of the shell. Brianne will paint the cast using photos to accurately render the colors and patterns of the shell.

all packed up and ready to head back to the studio for completion


We can’t wait to see- and touch- the finished result!!




1 response to Tortoise Shell Casting

  1. Katie Weeks says:

    This is super cool! What a neat collaboration for everyone! Trading strawberries for shell time seems like a fair deal for #12.

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