Step 1.
Take a square sheet, lay it flat on the table, with the bottom edge horizontal.
additional information
- If it is two-colored, place the colored side facing the table.
- The corners of the square are: top left, top right, bottom right, and bottom left.
Step 2.
Make a vertical valley fold by bringing the right edge to the left edge. Crease well and then unfold.
Step 3.
Make a horizontal valley fold by bringing the bottom edge to the top edge. Crease well and then unfold.
additional information
- You have now marked the medians of the original square.
Step 4.
Turn the folding from right to left and then position it as a diamond.
additional information
- The corners of the square are now: top, right, bottom, and left.
Step 5.
Make a valley fold, vertical, by bringing the right point to the left point. Crease well, then unfold.
Step 6.
Make a valley fold, horizontal, by bringing the bottom point to the top point. Crease well, then unfold.
additional information
- We have just marked the diagonals of the initial square.
- On the paper, one can feel that:
- The medians are mountains (the fold of the medians forms a ridge)
- The diagonals are valleys (the fold of the diagonals forms a trough)
Step 7.
Turn the folding from right to left, then rotate it to place the bottom edge horizontally.
additional information
- The corners of the square are now again at the top left, top right, bottom right, and bottom left.
- On the sheet, one can feel that:
- The medians are now in valley fold (the fold of the medians forms a trough)
- And that the diagonals are in mountain fold (the fold of the diagonals forms a ridge).
Step 8.
Bring the top edge to the bottom edge using the existing horizontal valley fold.
additional information
- We obtain 2 overlapping rectangular flaps connected by a horizontal hinge edge at the top.
- On the front and back faces of the shape, two oblique valley folds connect the middle of the hinge edge to the bottom right and left corners of the rectangular flaps.
Step 9.
Hold the folding between the thumbs and index fingers of both hands, so that the thumbs, which are in front, come into contact with the middle of the front valley folds, and the index fingers, which are behind, come into contact with the middle of the back valley folds.
additional information
- The shape is now no longer on the table, but held vertically in front of us, with the hinge edge horizontal and the flaps it connects pointing toward the table.
- The thumb and index finger of the right hand are to the right of the right oblique valley folds.
- The thumb and index finger of the left hand are to the left of the left oblique valley folds.
Step 10.
Give volume. To do this, push both hands down symmetrically until the thumbs and index fingers meet.
additional information
- The shape has opened and we obtain 4 triangular flaps of double thickness, one to the left in the left hand, one to the right in the right hand, one free toward the front, and one free toward the back.
Step 11.
Tilt the front flap to the left and hold it against the left flap.
Step 12.
Tilt the back flap to the right and hold it against the right flap.
Step 13.
Lay the folding flat on the table; the preliminary base is ready.
additional information
- We have a square diamond shape with a closed tip at the top and 4 triangular flaps of double thickness open at the bottom.
- You can feel a vertical valley fold in the middle of the shape that goes from the closed tip to the lower point of the square. This is the vertical axis of symmetry.
- The 4 panels are connected to each other by the closed tip at the top and the vertical axis of symmetry. There is a front left panel, a rear left panel, a front right panel, and a rear right panel.