How to Make a Coral Reef Diorama in a Shoebox

A coral reef is one of the best subjects for a first diorama. It's naturally layered, endlessly colourful, and forgiving: no one will tell you your coral is the wrong shape. It's also a classic school project, so this guide works for a quiet adult evening and for a Sunday-night "it's due tomorrow" emergency alike.

A little about real reefs

Coral reefs are built by tiny animals called coral polyps, which form hard skeletons of calcium carbonate over thousands of years. Many corals get their colour from microscopic algae living inside them. When water gets too warm, corals expel those algae and turn white, which is called coral bleaching.

The largest reef system in the world is the Great Barrier Reef, off the coast of Queensland, Australia. It stretches more than 2,000 km and is visible from space. Reefs cover a tiny fraction of the ocean floor but support around a quarter of all known marine species.

What you need

• A shoebox (lay it on its side so the open top becomes the front)
• Blue paint or blue paper in two or three shades
• Coloured paper or card: coral pinks, oranges, purples, yellows, and some greens
• Scissors, glue stick, and clear tape
• Thread or fishing line
• Optional: tissue paper, bubble wrap, sand, a small battery LED light

Step by step

1. Make the water. Paint or paper the inside of the box: dark blue at the back, lighter towards the top. If you can, run a gradient from deep navy at the bottom to bright turquoise near the top, where sunlight comes in. That one gradient does most of the work of making it look deep.

2. Add a sea floor. Glue sand, crumpled brown paper, or sandy-coloured card along the bottom.

3. Cut coral in three layers. This is the diorama trick (more on it in what is a paper diorama):

• Back layer: small, pale, simple coral shapes glued flat against the back wall
• Middle layer: medium-sized coral in stronger colours, standing on folded tabs a few centimetres forward
• Front layer: the biggest, boldest, most detailed pieces, near the opening

Branching coral is easy to cut freehand like antlers. Brain coral can be a round shape with wiggly lines drawn on. Sea fans work beautifully cut from tissue paper.

4. Add sea creatures. Cut out fish, a turtle, a seahorse, or a small shark. Draw both sides so they look right from any angle.

5. Hang them. Poke tiny holes in the top of the box, thread fishing line through each creature, and tape it on top. Hang them at different depths and distances so some swim in front of the coral and some behind.

6. Add texture. Bubble wrap makes a great sponge or bubble trail. A strip of green tissue makes swaying seagrass.

7. Light it. Lay a small LED light along the top edge, pointing down, or shine a torch in from above. Light falling from the surface brings the layers to life.

Make it a real reef

Some ideas if you'd like the diorama to teach something too:

• Label a few species: clownfish living in a sea anemone, a parrotfish, or a green sea turtle.
• Add a bleached section in white to show what warming water does.
• Base it on a real reef. The Great Barrier Reef is the classic choice.

A reef without the glue

The Wild Nature world in Paper Worlds includes a coral reef scene, built the same way: a blue-water background, then layered paper coral and sea creatures you place yourself. Alongside it are a flamingo lagoon and a forest waterfall. It's a calm way to "make" a reef on the evenings when the shoebox has already gone to recycling.

For more scene ideas, see our list of 12 sticker scene ideas.