Making a Spore Print

Turn invisible spores into visible art

Spores are usually far too small and too pale to notice. But there is a simple experiment that makes billions of them visible at once, arranged in a beautiful pattern: a spore print. All you need is a mushroom cap, some paper, a bowl, and a grown-up to help you.

What you need

• A fresh mushroom from a shop or a home grow kit (never a wild one)

• A sharp knife (a grown-up's job)

• A piece of white paper and a piece of dark paper

• A bowl or cup to cover the mushroom

• Soap and water for washing hands afterwards

Step by step

1. Ask a grown-up to help you choose a mushroom and gently twist or cut off its stalk, so the flat underside of the cap is showing.

2. Place the cap gills-down (or pores-down) directly onto the paper. Using both a white and a dark sheet, side by side under one cap, helps you see pale spores on the dark half and dark spores on the white half.

3. Cover the cap with a bowl to block draughts and keep moisture in. Air currents can blow spores away before they settle, so a still, covered space works best.

4. Leave it undisturbed for several hours, or overnight if you can wait.

5. Lift the bowl and very carefully lift the cap straight up. Underneath, you should see a delicate pattern of dust, echoing the shape of the gills or pores exactly.

Reading the colours

The powder you see is made of an enormous number of individual spores, all released from the same mushroom. Spore colour is a real clue that scientists use to help identify different kinds of fungi. Common spore print colours include white, cream, pink, brown, purple-brown, and even black. A mushroom that looks similar to another can often be told apart by comparing the colour of its spore print, because the cap colour and the spore colour do not always match.

If you look closely with a magnifying glass, you may even see that the print follows the exact pattern of the gills underneath the cap, like a fingerprint made of dust.

Staying safe while you explore

This is a wonderful activity, but a few safety rules matter every time.

• Only ever use mushrooms bought from a shop or grown from a proper kit at home. Never pick or use a wild mushroom for this, even if it looks similar to one you have used before, because telling fungi apart safely takes years of expert training.

• Always do this with a grown-up, especially for any cutting.

• Wash your hands with soap and water after handling the mushroom, before touching your face or eating anything.

• The mushroom you used for a spore print should be thrown away afterwards rather than eaten, since it has been sitting out and handled during the activity.

With those simple rules, a spore print is a completely safe way to see something astonishing: proof that a mushroom you can hold in your hand is quietly making billions of tiny living cells, all invisible until you know exactly how to look.