Some origami models are about the object you end up with. This one is about what you do with it afterwards: a fish on its own is a folded shape, but a fish hanging from a thread, or stuck on a window alongside a dozen others in different colours, is a small aquarium.

The folding could hardly be simpler. Nearly every step is a straight crease — halve the sheet, quarter it, eighth it, then bring the edges in to meet the lines you have just made. There is no reverse fold and nothing to tuck inside, which is why it works so well with children, or as a five-minute warm-up before something harder. Crease firmly at each step though, because the last few folds lean on the earlier lines being crisp.

Use paper that is coloured on one side — light blue is a nice touch, since the inside ends up reading as water — and keep a pen handy for the eyes.

How to fold the fish

STEP 1. Fold the paper in half and crease it, then open it out again.

STEP 2. Fold the edge towards the centre so the two marked points line up — about a quarter of the width of the sheet.

STEP 3. Fold it again, this time to about an eighth of the width. Crease it firmly, then open it out, leaving a single fold in place.

STEP 4. This is the result. Turn the paper over so the folded part is on top.

STEP 5. Fold along the marked line so it lines up with the centre line.

STEP 6. Fold it smoothly so the marked points meet.

STEP 7. Fold along the dotted line, keeping the crease on the marked line.

STEP 8. Fold the other side the same way.

STEP 9. Fold along the marked line so it lines up with the centre line.

STEP 10. Fold it in the direction of the arrow.

STEP 11. Turn it over, add the eyes and scales, and the fish is done.

Tips for folding

The folding itself is not difficult, but if you do not crease firmly at each step, the later folds become awkward.

Fold it with a light blue inside and hang it from a lid with a thread, and the fish looks as though it is swimming.

Stick one on a window and it looks like a fish swimming through the sky. Make several in different colours to complete a colourful aquarium.