Masu Box
This is a traditional Japanese design that dates back a couple of hundred years or so. The insert is a recent addition by the Italian origamist Paolo Bascetta who has kindly given his permission for it to be used here. To make the complete box you will need 3 identically sized squares of paper.
To make the box:
Begin with a square of paper, coloured on one side.
1. Lay the paper down - coloured side up. Align an edge of the square to run parallel with the HR.
2. Valley crease the entire square in half vertically from left to right and back.
The square now has a vertical crease through the centre.
3. Valley fold the entire square in half upwards.
You now have a rectangle. The long, closest edge to you is folded and parallel with the HR.
The long, furthest edge from you consists of 2 raw edges on top of each other, both parallel with the HR
4. Valley fold the top left hand corner of the upper layer down to the centre of the long, closest, folded edge.
What was the vertical left hand raw edge will now be lying along the closest, folded edge.
5. Repeat with the top right hand corner of the top layer.
6. Turn the paper over and arrange the long folded edge to be parallel with HR and closest to you.
7. Repeat Steps 4 and 5.
you should now have a RAT with its hypoteneuse, a folded edge, closest to you and parallel with the HR.
There are 2 smaller RAT-shaped flaps on the top and bottom surface of the larger RAT.
8. Bring the Right Angle Corner of the upper layers down toward you and lay it flat.
You should now have a square with folded edges and a smooth surface and sides at 45 degrees to HR.
The 4 corners of the original square are touching the table.
9. Turn the paper over and align folded edges of the square with HR.
10. The original square has now been "BLINTZED".
(Steps 9 and 10 were just for interest!)
Return the paper to the position at the end of Step 8 with the smooth side facing the ceiling.
Rotate model by 45 degrees so that edges are parallel with HR.
11. Valley fold the closest edge up to exactly meet the furthest edge - You are horizontally, valley folding the model in half.
12. Valley fold the top layer, top edge down to meet the new closest edge.
13. Turn the paper over, align long edges parallel with HR and repeat Step 12.
14. Unfold back to Step 8.
You should have a square with folded edges, a smooth surface and with 3 creases parallel to HR.
The creases go Mountain, Valley, Mountain. Rotate the model by 90 degrees.
15. Repeat Steps 11, 12 and 13.
Unfold the last 3 creases you made so that you have a square on the table, smooth surface facing to the ceiling, and aligned with hr.
Turn the paper over and align 1 edge with HR.
You should now have a square, aligned to HR, with the 4 corners of the original square in the centre and on the surface closest to the ceiling.
16. Unfold the left and right hand opposite corners fully and lay them flat on the table.
You should still have the 2 folded edges parallel with HR
Forming the box sides
17. Lift the furthest folded edge towards yourself using the valley crease that is parallel with HR, while,
simultaneously lifting the extreme left hand corner using the vertical valley crease (This is the third one in from the left)
When both edges are pointing upwards bring the closest folded edge up in a similar way to the first.
18. Where these edges meet there is some "extra" paper.
There is a diagonal mountain fold through the middle of this extra paper that runs alongside a raw edge.
Make the mountain fold definite by touching the 2 layers of paper together and, lying the triangular flap formed
alongside the now vertical left side of the model. This forms one side of the box.
You will need to fold both the horizontal sides at the same time.
19. If you have completed Steps 17 and 18 successfully you will have a long flap on the left
which you can then wrap over the left hand edge, covering the two triangular flaps lying against it, and down into the box and along its base without making any new creases.
You should now have 3 sides of the box formed.
20 Repeat Steps 17, 18 and 19 on the right hand side.
21. Congratulations! You have now folded the basic Masu Box.
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To make the lid;
22. Take another square of paper the same size as the first, and repeat Steps 1-9. Align the square with the HR. Unfold the left and right corners.
23. Take the box and undo it back to Step 16. Then valley fold the top edge down to the middle and the bottom edge up to the middle.
24. Take the box and lay it on top of the lid so that the left and right hand corners are exactly on top of the same corners on the lid.
25. Valley fold the top edge of the lid down over the top edge of the box. Then valley fold the bottom edge of the lid.
You should be able to feel, in the centre, that the edges of the lid do not quite meet.
This will make it just large enough to fit over the box snugly.
26. Unfold the lid and remove the box.
27. Fold the left and right hand corners back into the centre (Re-blintz the paper). Rotate the lid by 90 degrees and unfold the left and right hand corners.
29. Repeat Steps 24 - 26.
30. Complete lid and box in the same way. See Steps 17 - 20
31 Fit the lid onto the box and feel a warm glow of smugness!!
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Masu Box Divider
Description:
The divider fits inside the Masu Box in the form of a diagonal cross with a base.
Method:
1. Begin with the paper coloured side up. Aligned with the HR.
The original square should be the same size as the ones used for the lid and base.
2. Valley fold and unfold in half horizontally.
3. Valley fold in half from left to right vertically.
4. Valley fold the top right corner down to the left hand edge.
5. Valley fold the bottom right corner upwards to the left hand edge.
6. Turn the paper over from left to right.
7. Repeat Steps 4 and 5, but this time the corners are on the left and will need to be folded to the righthand edge.
8. Unfold the long folded edge and lay the paper down aligned with the HR and with the four flaps closest to the ceiling.
(Steps 2-8 can be better described as: Blintz the square with the coloured side on the outside.)
9. Divide the edges of the square into thirds and mountain crease horizontally and vertically.
This should give you a "Noughts and Crosses" pattern of mountain folds on the side of the paper that has the 4 flaps.
10. Ensure the tips of the flaps are all at the centre of the square and collapse the paper into a Waterbomb Base with the flaps on the outside.
11. Orientate the water bomb base so that the longest side of the triangle is parallel with HR, and the apex opposite it is nearest to you.
Swing the uppermost left hand corner across to the right and crease.
12. Turn the paper over and repeat Step 11.
13. Undo Step 10. and align the model with the HR.
14. Valley fold each corner into the nearest "Noughts and Crosses" intersection.
15. Remake the waterbomb base as in Step 10. with the lower corners folded up.
16. Arrange the paper so that the right angle corner that was the centre of the original square is pointing away from you.
You now have effectively 3 layers to the model:
a. Layer 1: A top layer (which itself is comprised of two layers of paper at its middle verticle crease;
b. Layer 3: A bottom layer (which itself is comprised of two layers of paper at its middle verticle crease;
c. Layer 2: A middle layer consisting of two vertical rectangular-type shapes. The two rectangular-type shapes are unjoined to each other, and you can waggle them past each other.
17. There is a horizontal valley crease near the top corner of layer 1.
Using this crease as a hinge, lift the nearest bottom edge of layer 1 up and over until layer 1 and 3 lie flat on the table. Layer 1 will by lying on top of a little triangle on the table.
18. As a result of lying layer 1 flat on the table, layer 2 (middle layer) will have swung upwards to be perpendicular to layers 1 and 2, with the two rectangular-type flaps pointing up at the ceiling.
Hold each flap between your thumb and index finger of each hand and pick the paper up off the table.
Using the mountain crease in the middle of the paper as a hinge, swing the flaps away from each other as far as they will go. This should rotate them through 90 degrees so that the longer edge of the rectangular-type flap has moved from a sticking up in the air to a horizontal orientation.
19. The divider is complete and will fit snugly into the Masu Box.
20. You now deserve an extra glow of smugness! Well done.