## This paper bellows works! The larger the square of paper used, the more air you'll be able to push in and out of it.

In order to fold this project, you'll need a square of paper and a place to work. A sheet of plain, white copy paper works well for practice. Move on to colored or patterned paper, if desired, after you've successfully folded this model once or twice. The paper you use should be heavier than the average sheet of lined notebook paper.

You'll also need to find a suitable place to work. Folding against a hard, flat surface works best for making the sharp creases and accurate folds needed for a successfully completed model. A table, hardback book, or even a floor will do. Make creases even sharper by running a pencil or ruler edge over each one as you work.

1. Position a square of paper on your work surface so that the edges are facing up and down, left and right. If you are using two-sided paper, make sure that the color you want for the exterior of the bellows is facing down.

2. Bring the left edge over to meet the right edge. Crease and unfold.

3. Bring the top edge down to meet the bottom edge. Crease and unfold.

4. Turn the square over and position it so that its points are now facing up and down, left and right.

5. Bring the left point over to meet the right point. Crease and unfold.

6. Bring the top point down to meet the bottom point. Crease and leave folded.

7. Grasp the left and right points of the resulting triangle and push inward. This will cause the model to collapse along the folds you just made. The result will be another triangle shape with folded flap sticking out from the back of the model and another sticking out from the front.

8. Fold the front flap to the left and fold the back flap to the right so that your model will lie flat. Position your model so that is flat against your work surface and the open end is facing toward you.

9. Bring the left point (top layer only) up to meet the triangle's top point. Crease and leave folded. Repeat for the right point.

10. Turn the model over and repeat Step 9.

11. Bring the lower left edge of the model over to meet the vertical center line. Crease and unfold. Repeat for the lower right edge.

12. Bring the upper left edge of the model over to meet the vertical center line. Crease and unfold. Repeat for the upper right edge.

13. Turn the model over and repeat Steps 11-12.

14. Bring the left point of the model (top layer only) up and pinch it in half so that its folded edge is facing down. As you pinch, move toward the center of the model. The upper left edge and lower left edge of the model should fold down along the crease lines made in Steps 11-12. The result will be a long triangular flap on the left side of the model with a folded point sticking straight out toward you.

15. Repeat Step 14 for the right side of the model. Turn the model over (fold the resulting points flat while you work the other side of the model).

16. Repeat Steps 14-15.

17. Position the model so one set of points made in the previous steps is pointing toward the left and the other is pointing toward the right. For each set of points, secure by placing one point inside the other.

18. Grasp the model by its points and push in and out to work the bellows.