Unfold in reverse order

Keep track of the fold order

Fold the right half of the square to the left. Then fold the bottom half upward. The paper now occupies the top-left quarter.

Punch one hole through all the folded layers, away from either crease. The dashed outline shows the original sheet.

1. Fold right to left.

2. Fold bottom to top.

3. Punch through the folded layers.

First undo the bottom-to-top fold. The hole gains a matching hole below the horizontal crease, at the same distance from it.

Then undo the right-to-left fold. Mirror both holes across the vertical crease. These two off-crease folds leave four holes on the open sheet.

1. Begin with the punched quarter.

2. Open the horizontal crease: two holes.

3. Open the vertical crease: four holes.

Again, fold right to left, then bottom to top. This time the punch is near the top of the folded quarter.

The hole has moved, but the fold order is the same. Choose the crease you would open first.

Right to left, then bottom to top. A new hole position.

Which crease do you open first?

Show the answer

The horizontal crease

Open the horizontal crease first because the bottom-to-top fold happened last. Each hole is mirrored below that crease before the other fold opens.

Enable JavaScript to answer interactively and save your place.