How to Fold an
Origami Waterbomb Base

There are other ways to fold this base, but from the many classes I've taught, I've found this method more often achieves good results and teaches a valuable skill, the squash fold.

Materials

A single piece of square paper

The origami waterbomb base is also known as the balloon base or triangle base.

Like the square base, or preliminary fold, it's called a base because it's the starting point for many origami models.

If you can fold a square base from memory, you already know the waterbomb base.

Just think of it as starting 90º (or ¼) turn from the square base.

I start folding a square base with by folding the paper in half side to side, so I start the waterbomb by folding it in half corner to corner.

1. Start with the paper white side up or down, according to the directions for the model you will make from the base. Fold the paper corner to corner. Unfold and fold the two other corners together. Unfold.
2. Fold in half side to side.
3. Fold in half again, forming a square.
4. Lift up the square you just folded and open it.
5. Squash it down into a triangle. Be sure to use existing creases - don't make any new ones.
6. Turn the whole piece over.
7. To make the next step easier, re-crease the fold highlighted in white by folding the square flap over, as indicated by the arrow. Fold all the way over and flatten. Then lift and open like you did on the first side.
8. Squash-fold a triangle on this side...
9. YOU'RE DONE! This is the origami waterbomb base.