A mountain fold is just an upside down valley fold. One way to make it is to turn the paper over and make a valley fold: either horizontally, vertically, or diagonally, as appropriate.
To see a larger picture of each substep, just select the corresponding image.
The mountain fold is indicated by a dash-dotted line. In this example, we will fold the left edge behind to the centerline. First, we turn the paper over from side-to-side, or book-fold, as appropriate.
We valley fold on the dashed line, which corresponds to the mountain-fold line on the other side.
In the middle of the valley fold...
Creasing the valley fold.
After completing the valley fold, we either turn the model back over, or undo the book-fold.
The finished mountain fold.
Copyright 1995-96, 98-99 by John Paulsen. You can send him your comments.
Last updated July 23, 1999.