Exploring Eggshell Ceramics

As I was browsing for inspiration online, I cam across a post about eggshell ceramics and was instantly intrigued. My family goes through lots of eggs, so the thought of turning all those shells into something useful (and kind of beautiful) really caught my attention.

As I looked deeper into how eggshell ceramics are made, I quickly realized that the information online was quite confusing—different sources suggested different materials and ratios, even when using the same ingredients. That left me wondering: why are there so many variations, and which ones actually work? Can we use other ingredients?

So, I decided to run some hands-on experiments of my own.

The idea behind eggshell ceramics is pretty simple: you mix powdered eggshell with the right binder material to hold everything together. When it comes to binders, there are really two things that matter: how strong the binder is, and how malleable the mix is.

You can use eggshell ceramics for all sorts of things—indoors as little vases, plates, or storage containers, and outdoors as garden decorations that even add nutrients back into the soil.

In this post, I’d like to share what I discovered.

Material:

1. Eggshells
2. Gelatin power, Glycerin, Salt (Option 1)
3. Sodium Alginate, Vinegar (Option 2)
4. Mod Podge, Elmer's Glue, Hide Glue (Option 3)
5. Water

Tools:

1. Blender
2. Oven
3. Cooking pot
4. Scale
5. Measuring spoon/cup
6. Container or bowl
7. Molds (Hard plastic, silicon, or glasses)
8. Sieve

First, gather your eggshells. If possible, peel off the inner membrane or just give them a good wash. Another option is to boil them for about 15 minutes to get rid of any bacteria. After that, let the shells dry completely.

Bake the eggshells at 350°C for about 15 minutes.

Tip: Don’t over-bake them—too much heat can change their color. You just want them dry and brittle, which makes the blending step way easier.

Blend the eggshells until they turn into a fine powder. If you want an extra-smooth texture, you can sift the powder through a sieve.

Tip:

[1] Wear a mask while grinding—eggshell dust can get everywhere!

[2] Consider sorting eggshells by color before blending. This makes it easier to create ceramics in natural eggshell tones or experiment with variations by mixing different proportions. Even if you plan to add food coloring, keeping some white shells separate will help you achieve your desired shade more easily.

Start by measuring out the agar-agar powder and water based on the ratios in the table. Gently heat the mixture until it starts to form a sticky mass. Next, add the eggshell powder and stir well. Please refer to the table for the ideal proportions. Once it’s mixed, pour it into a mold—or sculpt it quickly by hand before it sets if feasible. Note the small cup shape shown was made by pressing a small glass cup inside the bigger mold after the mixture was poured in.

Here’s what we found during testing:

1. Using molds: The first recipe gave the best results — 45g eggshell powder, 9.5g gelatin powder, and 135ml water. More water makes the process easier when using a mold. However, deeper and bigger molds do not work well, as the product tends to form cracks.
2. Shaping by hand: The third recipe worked better for simple, hand-shaped pieces, though the results were too small to be practical. Again, bigger ones will crack.

The key factor seems to be the eggshell-to-water ratio. The first recipe had just the right balance. Interestingly, adding more binder didn’t necessarily improve the outcome.

One thing to note: when using agar-agar as a binder, the finished pieces shrunk—sometimes by as much as 10–30%. I think it might be related to the amount of water used.

Tip: [1] Agar-agar sets fast! Have your molds ready before you start, since the mixture begins curing within minutes. If you’re using molds, remove the piece once it starts to shrink will typically reduce the chance of cracks.

[2] If possible, take it out of the mold as early as possible (once the basic form can hold by itself) so to get more evenly distributed air exposure.

Most of the guides we found on making eggshell ceramics mentioned gelatin but never clarified whether it meant plant-based or animal-based. So, we tested both. In particular, we tried using beef gelatin powder at different ratios.

Here’s what we ran into:

1. It takes forever to dry — It's way too long to be practical.
2. A strange odor develops during the process.
3. The results are inconsistent — whether heated or not, the gelatin-and-water mix just isn’t sticky enough to blend evenly with the eggshell powder. After a long wait, some parts turned leathery, some formed odd irregular shapes, others simply never set at all.

Because of these issues, we wouldn’t recommend using beef gelatin powder as a binder.

Another popular binder for eggshell ceramics is sodium alginate. We tested two different mixes and compared the results (see table). Here’s the method that worked better for us:

1. Make a 2% sodium alginate solution. Mixing alginate straight into water won’t give you a smooth blend right away—you’ll see little lumps at first. Just let the mixture sit for a day, and it will even out.
2. Prepare the mold. Brush a thin layer of vinegar onto the surface of the mold.
3. Mix and pour. Add eggshell powder to the alginate solution according to the ratio in the table, stir well, and pour into the mold.
4. Seal with vinegar. Brush a light layer of vinegar along the edges and top of the mold.
5. Drying time: Depending on the size of your piece, it may take 2–7 days to fully dry.

This method allows you to create slightly larger objects than with agar-agar, and it also does a better job of capturing fine details from the mold.

One concern is the long drying time. It also requires the object to have a certain thickness in order to avoid cracks. One remedy is having some extra mixture ready to seal any gaps that appear.

Overall, I like this method as you have a very lenient window of time to shape the object. However, it does take a LONG time to dry and needs extra attention.

We tried out three types of glue as binders: Elmer’s glue and Mod Podge (since they’re easy to find and relatively cheap), and hide glue (because it’s biodegradable). The results are compared in the table above.

Glue turned out to be the strongest binder of all, which allowed it to hold its shape very well.

Now let’s try a fun project! For this one, I wrapped a broken balloon around a small glass jar and filled it with a mixture of eggshell and hide glue. After securing the jar’s top with a rubber band, I shaped the mixture over a rock. Then, I gradually removed the balloon wrap to allow it to dry.

I also tried making art with pebbles. First, I made several eggshell pebbles with small holes. I then threaded a wire through them to form different shapes.

We also made small mushrooms to decorate our plants indoors, and outside in the garden. They are biodegradable and can release nutrients into the soil as time goes by!

In our experiments with different methods and binders for making eggshell ceramics, we tested commonly recommended ingredients as well as a few new ones we came up with ourselves. Some are biodegradable, others are not; some work best for molding, while others are better for hand-sculpting.

One thing we noticed: biodegradable binders usually aren’t very strong, so they’re better suited for smaller pieces. If you want to make larger items without worrying about cracks, stronger binders like glue are a safer choice.

Another factor to consider is the cost. Most biodegradable binder materials are much more expensive than their non-biodegradable counterparts.

I hope our exploration inspires you to try reusing everyday waste—like eggshells—and turning it into something super fun, useful, and even beautiful!