Preliminary Base

Traditional

The Preliminary Base is so named because several other classical origami bases are derived from it, such as the Bird, Frog and Lily Bases. You can also make a Waterbomb Base from a Preliminary Base simply by passing the center through the plane connecting the square’s corners, turning it inside out! (Note that the color will now be on the inside.)

1 Begin color-side up if using standard origami paper. Valley-fold bottom corner to top corner. Unfold. Rotate 90 degrees.

2 Valley-fold bottom corner to top corner. Unfold. Turn over. Rotate 45 degrees.

3 Valley-fold bottom edge to top edge. Unfold. Rotate 90 degrees.

4 Valley-fold bottom edge to top edge. Unfold. Rotate 45 degrees.

5 Use the existing creases to collapse the square. Each crease must fold independently from the center point.

6 Collapse in progress.

7 The Preliminary Base. Notice that it has an open end, which is at the bottom, and opposite, a closed corner.