Origami · folding only · Confident · about 25 minutes

Box with Fitted Lid

No scissors · No glue · No adult help needed

Square of paper for the box, 150 x 150 mm (6 x 6 in)
Slightly bigger square for the lid, 159 x 159 mm (6 1/4 x 6 1/4 in)

Finished

Blue dashes: valley fold (toward you). Pink dash-dot: mountain fold (away from you). Thick line with scissors: cut. Yellow: glue.

Start. Start with the 150 mm box square, white side up, flat edges at the top and bottom.
1. Fold and unfold: Fold the square in half corner to corner, then unfold. Fold it in half the other way and unfold.
2. Valley fold: Fold all four corners in to meet at the center point.
3. Rotate: Turn the paper partway around so a flat edge is at the bottom, like a square.
4. Fold and unfold: Fold the top edge down to the center line and unfold. Fold the bottom edge up to the center line and unfold.
5. Fold and unfold: Do the same from the sides: fold the left edge and then the right edge to the center line, unfolding each time.
6. Unfold: Unfold the top and bottom corners. Leave the left and right corners folded in.
7. Valley fold: Fold the left and right sides up along the creases so they stand as two walls. The ends start to rise and their corners fold inward.
8. Push: Push the far end up straight so it becomes the third wall. Its corners fold inside against it.
9. Valley fold: Fold the point over the far wall and down into the box. Press it flat on the floor so it holds the corners in.
10. Put together: Repeat at the near end: push it up into a wall, then fold its point over and down into the box. The box is done.
11. Put together: Now fold the lid: take the bigger square (159 mm, 6 1/4 in) and fold it exactly like the box, steps 1 to 10.
12. Place: Turn the lid upside down and lower it over the box. Its floor is about 3 mm wider, so it slides down over the walls.

If something goes wrong

The lid will not go on. Check that the lid square really is 9 mm (1/4 in) bigger, and that its corners met exactly at the center in step 2. Press the box walls straight and try again.
The lid is loose and falls off. The lid square is too big. Try a square only 5 mm (about 3/16 in) bigger than the box square.
The walls lean outward. Crease the wall folds firmly, and press the folded-in points flat on the floor of the box. They lock the walls in place.
The corners will not fold inside. Pinch the corner crease from the outside while you push the end up; it folds in along the creases you made in steps 4 and 5.