Preliminary Base Instructions
- Start with a square sheet of paper with the colored side facing up.
Fold the paper along the diagonal in both directions to form an X shaped crease. Unfold.
- Flip the paper over so the white side is facing up.
Fold the paper in half left to right. Unfold.
- Push the right and left edges inwards towards one another. A flap of paper will come towards you (red dot) and another flap will be created behind the model (blue dot).
- Swivel the front flap to one side. Swivel the back flap the other direction. Use the location of the dots to help visualize the process.
- Done! The origami preliminary base looks like a square that is ¼ the size of the original paper. It has a total of 4 flaps. The typical orientation is to have the flaps arranged two on the left and two on the right.
The preliminary and waterbomb bases are the bread-and-butter of the origami world. There are many origami models which start with these two bases. In fact, the two bases are inter-convertible: if you invert the preliminary, it will become a waterbomb base. The opposite is also true, a waterbomb base can be inverted to form the preliminary. The only issue being that the colors (color or white) would be inverted too.
The instructions shown here is just one of the many ways to make the base. You can see this base being used in this Fluted Diamond ornament.