What is Plaster Casting? Fun and Creative Activity Ideas for Kids

Plaster casting involves pouring a liquid plaster mix into a mould, which then hardens to create a solid object. The process is generally simple, safe (with supervision), and provides endless opportunities for children to experiment with shapes, textures, and colours.

From handprints to custom figurines, the possibilities are limited only by imagination, making it an ideal craft project for kids of all ages, so read on for all the information you need about plaster of Paris cast making.

Plaster has a long and fascinating history. Its origins date back at least seven thousand years to the Middle East, where it was used for building and decoration. The Greeks used plaster, the ancient Egyptians even used plaster within the great pyramids, and it has been used in Europe since Roman times.

The most commonly used type of plaster is made from gypsum, a soft mineral found all over the world. It’s used in all sorts of ways, including in the construction industry, for agricultural purposes, in medicine (casts for broken bones are made from gypsum plaster), and of course arts and crafts.

When you heat gypsum, it becomes a fine powder that can be mixed with water to create plaster. Its ability to harden quickly and capture fine details has made it a popular choice as a building material, as well as for art, sculpture, and children’s crafts.

Gypsum comes from the Greek word gypsos, which translates literally to ‘plaster’, but the stuff you’ll use in your plaster cast moulds today is called ‘plaster of Paris’.

The name ‘plaster of Paris’ originates from the abundant gypsum deposits found in Montmartre and the surrounding areas of Paris. The town of Montmartre in northern Paris is most famous for the Sacré-Cœur, a church which sits on top of a hill overlooking the whole of Paris, but the hill it sits on contains a huge deposit of dehydrated gypsum, hence the name plaster of Paris. The high-quality gypsum mined in this region made the city famous for its production, leading to the term becoming synonymous with this versatile plaster material.

So if you’re interested in undertaking plaster casting as a hobby, what can you make with plaster of Paris plaster casts, and what tools do you need to start a project? Let’s find out.

Plaster casting is fun, creative and very hands-on (you may get a little bit messy!) and it’s really well-suited to kids’ activities because it’s so easy to use and incredibly versatile.

You can make a wide variety of projects, such as casting animal shapes, creating masks, making jewellery, or even capturing handprints or footprints as keepsakes. There are loads of different types of plaster cast moulds in all shapes and sizes to choose from in hobby shops and online.

The beauty of plaster of Paris cast making is that once the plaster is put into the mould, it sets relatively quickly, meaning you can enjoy the results of your work within a short time. After the plaster hardens, you can paint the creations, adding a personal touch to your designs. This makes it a fantastic way for kids to explore their artistic side.

To get started with plaster of Paris plaster cast making, all you need are a few basic tools.

Plaster of Paris

The star of the show! This is the primary material needed for the casting and it usually comes in powder form. Mixing the plaster with water will create the casting material and the instructions for how much of the powdered plaster and water you’ll need for the right consistency will be on the packet.

Silicone Moulds

Silicone moulds are ideal for plaster casting because they’re flexible and easy to use. They come in all sorts of shapes and sizes, including animals, objects, or even custom-made shapes. You’ll even find moulds for special occasions, like Christmas trees, Easter eggs, and pumpkins for Halloween. As well as in the shops listed above, you also often find silicone moulds in the home baking aisle of your supermarket because they’re also used for making cakes!

Mixing Bowl & Spoon

You may have these at home, but you’ll need a disposable or old mixing bowl (plastic or ceramic) and a spoon or spatula to mix the plaster of Paris with water. Make sure they’re not used for food preparation afterwards.

Protective Gear

While plaster of Paris is generally safe, it’s useful to wear aprons or old clothes to avoid any mess, and latex gloves can help prevent direct contact with the plaster. Also, having an old table cloth or newspaper to cover the work area will help keep things tidy.

Stirring Stick

After pouring the plaster into the mould, a small stirring stick, like a lolly stick, can be used to smooth out the surface and remove any air bubbles.

Water & Damp Cloth

You’ll need water for mixing and a damp cloth for quick cleanups. Plaster hardens quickly, so it’s useful to have some cloths handy to wipe off spills immediately.

Paint & Brushes

Once the plaster has set and the moulds have been released, you can add a personal touch to your creations with acrylic paints. Small brushes work best for detailed work.

One other thing to mention is that if you’re making things like badges or brooches, you can add a closed safety pin to the plaster before it hardens.

No introduction to Paris plaster cast making is complete without a set of basic steps to start your crafting journey:

Step 1 – Prepare Your Work Area

Cover your workspace with an old teatowel, some newspaper, or a plastic sheet to protect surfaces from spills. Make sure you have all your materials ready before you start, and get your old clothes, aprons and gloves on!

Step 2 – Mix the Plaster

Measure the plaster of Paris and water according to the instructions on the packaging (it’s usually two parts plaster to one part water but check before you start). Pour the water into your mixing bowl first, then slowly add the plaster while stirring. Stir gently with a spoon or spatula to avoid creating air bubbles, until the mixture has a smooth, lump-free consistency like pancake batter.

Step 3 – Pour the Plaster in the Mould

Once your mixture is smooth, carefully pour the plaster into the silicone moulds. Fill them evenly, and use your small stirring stick to smooth the surface and remove any air bubbles.

Step 4 – Let the Plaster Set

Allow the plaster to set in the moulds. The time it takes to fully harden depends on the size of the mould, so please refer to the instructions on the packet. The plaster will harden as it dries.

Step 5 – Take Your Casts out the Moulds

Once the plaster has completely set and is hard to the touch, gently remove the cast from the silicone mould by flexing the mould and carefully pulling out the cast. If it feels soft or delicate, give it more time to harden.

Step 6 – Paint Your Casts

After you’ve taken the casts out the moulds, leave them to dry completely for a few more hours before you start painting. Non-toxic acrylic craft paints are the most common type of paint to use on your plaster of Paris casts, but you can also use water-based gloss enamel paints that provide a shinier finish.

And that’s it! Once the paint is dry, your plaster cast is complete! You can display it, give it as a gift, or use it as a fun decoration.

So what is plaster casting? It’s a great activity that encourages kids to use their creativity while learning new skills. With just a few simple tools, you can create unique, lasting sculptures and enjoy the process of turning liquid plaster into solid art. Whether it’s for a rainy-day activity at home, a school project, or a birthday party, plaster casting is a great way to inspire artistic exploration in young minds.