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EASY · 15 CM SQUARE · 6 STEPS

Masu Box

A traditional box that locks itself together. A 15 cm square makes a box about 5 cm across; fold a second from a square 5 mm larger for a lid.

Valley foldUnfoldMountain fold
Scroll to fold ↓
STEP 01

Crease the diagonals

Valley foldUnfold

White side up, fold in half corner to corner both ways, unfolding each time. The creases mark the centre.

STEP 02

Fold the corners to the centre

Valley fold

Fold all four corners in to the centre point. This is a blintz fold.

STEP 03

Edges to the centre

Valley foldUnfold

Turn the square so an edge faces you. Fold the top and bottom edges to the centre line and unfold. Repeat with the left and right edges. Crease firmly: these lines become the walls.

STEP 04

Open two flaps

Unfold

Unfold the left and right corners, leaving the top and bottom flaps folded in.

STEP 05

Raise the walls

Valley foldMountain fold

Fold the top and bottom walls up so they stand straight. As you lift each end, push its corners in along the diagonal creases: the end rises as a third wall with a pointed flap above it.

STEP 06

Fold the flaps into the box

Valley fold

Fold each pointed flap down over its wall and into the box so the tip reaches the centre of the floor. Run a fingernail along the rims to lock the walls in place.

DONE

Finished box

Square up the corners from the inside. For a lid, fold a second box from a square about 5 mm larger and slip it over the first.

About the masu box

The masu is a square box named after the wooden cups once used in Japan to measure rice. A masu held a fixed volume, and wooden masu are still used today to serve sake at celebrations.

The paper version locks together with no glue or tape. Its strength comes from the way the walls are built: each wall is several layers thick, and the end flaps fold over the walls and into the box, clamping the corners in place.

Masu boxes are practical as well as decorative. They make good trays for small items, gift boxes and party favours, and a box folded from a slightly larger square fits over the first as a lid.

Tips and troubleshooting

  • Make every crease sharp before you raise the walls. The collapse in step 5 follows the creases you made in steps 1 to 3.
  • If the corners won’t fold in neatly, raise one long wall first and push its corners in, then raise the opposite wall.
  • Fold the end flaps firmly over the rims so their tips reach the centre of the floor. That is what locks the box.
  • Card-weight paper makes a sturdy box but is hard to fold; standard origami paper or wrapping paper is easier.

Common questions

How big is the finished box?

About a third of the width of the starting square. A 15 cm square gives a box about 5 cm across and 2.5 cm deep.

How do I make a lid?

Fold a second box from a square about 5 mm larger on each side. It slips over the first box.

How do I make the box stronger?

Use thicker paper, or fold the box from two sheets placed back to back. Crease the rims hard so the flaps lock tightly.

Traditional, Japan. Instructions and diagrams written for this site.