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 table side.
  • 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 over to the left edge.

Crease well and leave folded.

additional information

  • You get a rectangle with double thickness in a vertical position.

Step 3.

Make a horizontal valley fold by bringing the bottom edge up to the top edge.

Crease well and then unfold.

Step 4.

Make a vertical valley fold by bringing the right edge over to the left edge.

Crease well and then unfold.

additional information

  • The vertical axis of symmetry has just been marked. It is a valley fold.

Step 5.

Form a vertical valley fold by bringing the right edge from right to left along the valley fold marking the vertical axis of symmetry.

Crease well through both layers and leave it folded.

Step 6.

Form a vertical valley fold by bringing the left edge from left to right along the valley fold marking the vertical axis of symmetry.

Crease well through both layers and leave it folded.

additional information

  • You obtain a vertical rectangle with, at the front, two free double-thickness rectangular flaps (one right and one left), each attached to the base rectangle by a hinge edge.
  • The junction of these two flaps forms a slit along the vertical axis of symmetry.

Step 7.

Using the valley fold of the vertical axis of symmetry, fold the right part of the crease over the left part.

additional information

  • The fold is a narrow rectangle in a vertical position, with a hinge edge on the right.

Step 8.

Rotate the model on itself so that the hinge edge becomes the lower horizontal edge.

additional information

  • In the middle of the fold, you can feel a mark corresponding to the vertical axis of symmetry.

Step 9.

Starting from the middle of the hinge edge, make an oblique valley fold by bringing the right part of the hinge edge along the vertical axis of symmetry.

Crease well through all layers and let it crease.

Step 10.

Starting from the middle of the hinge edge, make an oblique valley fold by bringing the left part of the hinge edge along the vertical axis of symmetry.

Crease well through all layers and leave it folded.

additional information

  • The model is now a pentagon.

Step 11.

Turn the two previous oblique folds into inside reverse folds.

additional information

  • The overall shape of the fold is a pentagon.
  • The right and left parts of the fold are vertical four-panel double-thickness accordions.
  • A vertical slit separates the two accordions.
  • The front lower and rear lower parts correspond to two triangular pockets whose opening is horizontal on the 12 o'clock side.
  • One can also say that there is a right front flap, a right rear flap, a left front flap, and a left rear flap.

Step 12.

Fold the right front flap over the left front flap.

Step 13.

Turn the model over from right to left.

Step 14.

Fold the right front flap over the left front flap.

additional information

  • The front and back faces all become smooth.
  • The fold is a pentagon with a vertical left edge, a horizontal top edge, a vertical right edge, and two slanted bottom edges that meet at the bottom tip.

Step 15.

Along the imaginary horizontal line connecting the bottom left corner and the bottom right corner of the pentagon, make a horizontal valley fold by bringing down the top part of the front flap over the lower tip of the fold.

Crease well and let fold.

Step 16.

Turn the model over from right to left.

Step 17.

Make a horizontal valley fold by bringing the top edge of the fold down along the bottom edge.

Crease well and let fold.

additional information

  • The fold is a rectangle in a vertical position consisting of:
  • A vertical rectangular front flap, with a slit on the ceiling-side face.
  • A thick middle triangular flap, whose free tip is oriented at 6 o'clock. This middle flap resembles the base of a water bomb.
  • A rectangular rear flap in a vertical position, with a slit on the table-side face.
  • One can also say that there is a front right flap, a rear right flap, a front left flap, and a rear left flap.

Step 18.

Fold the front left flap inside the front right flap.

additional information

  • The front and rear flaps are no longer symmetrical.
  • The front flap covers the right part of the model.

Step 19.

Using the vertical axis of symmetry, fold the front flap onto the left part of the model.

additional information

  • On the upper part of the model, you can feel a raised triangle that will correspond to the buttocks.

Step 20.

Fold the right side of the fold over to the left.

additional information

  • There is a vertical slit on the ceiling side of the front flap.
  • There is a left flap, a front right flap, and a rear right flap.

Step 21.

Tilt the front right flap inside the left flap.

additional information

  • Congratulations, you have finished making your trousers.