The inside reverse fold is an origami skill. It is a low intermediate skill in the origami tech tree.

Currently, this page is a first try at text instructions for making the inside reverse fold. This page needs pictures (and maybe an animation).

Here is one way to do the inside reverse fold:

  1. Start with a flap. Decide where you want to make the inside reverse fold.
  2. Valley fold the paper along the chosen line.
  3. Unfold to step 2.
  4. Separate the two hidden layers of paper, so that you are half-way between step 1 and step 2. You will see the vee-shaped pair of creases formed in step 2.
  5. Push the tip of the paper into the gap you just made.
  6. One of the creases (of the vee) will already be in the correct direction (a valley fold as seen from inside; a mountain fold as seen from outside). The other crease will be in the opposite direction. Reverse the second crease, so that both creases are valley folds as seen from the inside, and [mountain fold]s as seen from the outside.
  7. Reverse the lower left edge, so that it is a mountain fold as seen from the inside, and a valley fold as seen from the outside.
  8. "Pop" all three creases into place.
  9. Close up the model again.
  10. The inside reverse fold is done. (Notice how you reversed the folds to put the tip inside the model--thus the name.)