
In origami mountain-fold, the fold done in the flap or layer of paper is backward.
When unfolded, the crease forms a peak that resembles a “mountain ridge”. Hence, called mountain-fold.
To make a mountain-fold, follow the following tip:
– Turn over the paper
– Make valley-fold.
– Again, turn over the paper to the original position.
The two basic origami folds are mountain-fold and valley-fold. The valley-fold is the opposite of the mountain-fold. The mountain-fold is rarely used whereas in all origami models there is a valley-fold.
Note: Mountain-fold is folded horizontally, vertically, diagonally etc.
Example of mountain-fold
Step 1: Take an origami paper and position it.

Step 2: Mountain-fold the paper diagonally at the top-left edge. And, crease the paper to form a mountain-fold.

Why is it called mountain-fold?
Step 1: Take an origami paper.

Step 2: Mountain-fold the left edge of the paper to meet the right edge. Then, crease the fold.

Step 3: Unfold the fold made in Step 1. The crease formed in the unfolded paper, makes the paper resemble a mountain ridge. Hence, called a mountain-fold.
