This

traditional origami base is used as the beginning for the classic model the

waterbomb, and many other origami models. It is a must for

beginners.

Begin with a perfect square of paper. Origami paper is easiest to work with and you should try to get (it's extremely cheap at art supply stores), but a square of computer paper will work too. If your paper is the same color on both sides, mark a large "C" or similar symbol on one side to represent the colored side.

Begin with your colored side facing up. Book fold and unfold: Fold the square in half vertically, crease, and unfold. Then, fold the square in half horizontally, crease, and unfold. Make sure that your creases are crisp and accurate.

Flip the paper over so that the white side faces up. Diaper fold and unfold: bring one pair of opposite corners to meet, crease, and unfold. Then, repeat with the other set of corners, but after creasing, don't unfold.

Hold the resulting triangle shape between your thumbs and forefingers, each hand gripping at the top (the fold). Press in and down and the bottom points should begin to point outwards until...

A shape (viewed from the bottom) that looks like an "X" or "+" should appear. Pair the legs together to make a group of two on the left and a group of two on the right, then flatten along the creases.

You should end up with a triangle shape, with hidden layers of paper inside.

When turned inside out, this base becomes the

preliminary base.

### Models That Utilise the Waterbomb Base

Stellated octahedron
Gyroscope
Butterfly Ball
Masu Box Divider
Five Diamond Decoration
Waterbomb