A squash fold is a fundamental origami technique where you open a flap of folded paper, then press it flat to create a new shape. It’s one of the most common folds in origami, appearing in everything from simple cups to complex animals, and it’s often the first intermediate technique beginners encounter after learning basic valley and mountain folds.
How a Squash Fold Works
The core idea is simple: you take a section of paper that already has a crease or fold, lift it open so it forms a pocket, then flatten that pocket down symmetrically along a new crease line. The result is a shape that looks different from what you started with, typically a diamond or triangle where there was previously just a folded edge.
What makes it a “squash” fold is exactly what it sounds like. You’re squashing an open pocket of paper flat. The paper doesn’t tear or stretch. It just redistributes into a new configuration because the existing creases allow it to collapse in a controlled way.
Step-by-Step Process
While the exact setup varies depending on the model you’re folding, the basic sequence is always the same:
- Start with a folded flap. You need a layer of paper that’s already been folded over, creating a pocket or edge you can open.
- Open the flap. Lift the top layer away from the bottom layer, inserting a finger to separate them and create an opening.
- Align the crease. As you open the pocket, guide the top edge so that the fold line of the flap lines up with a center line or reference point on the model.
- Press flat. Once aligned, press the paper down firmly and crease it flat. The flap should now sit symmetrically in its new position.
The key to a clean squash fold is alignment. When you press the paper down, the original fold line of the flap should land directly on top of the center crease or guideline beneath it. If it’s off to one side, the result will be lopsided, and later folds in the model won’t line up correctly.
Where You’ll Encounter It
The squash fold shows up constantly in origami because it’s one of the primary ways to transform a simple folded edge into a more complex shape. The preliminary base (sometimes called the square base), which is the starting point for dozens of traditional models, uses squash folds to convert a folded triangle into a layered diamond. From there, models like the crane, lily, and frog all build on that foundation.
You’ll also encounter squash folds in the middle of more advanced models, where they’re used to shape legs, wings, petals, or other features. Whenever instructions tell you to “open and flatten” a flap, that’s a squash fold, even if the diagram doesn’t use the term explicitly.
Reading Squash Folds in Diagrams
Origami diagrams use a standardized set of symbols, and squash folds are typically indicated by a combination of two things: a hollow arrow showing where to push or open the paper, and a regular arrow showing the direction to flatten it. Some diagrams simply label the step as “squash fold” or “push and flatten.” Older or more compact diagrams may group it under the general category of push or reverse-fold actions, so context matters.
If you see an arrow pointing into a pocket or flap combined with a dotted line showing where the paper will end up, that’s your cue. The dotted line represents the new position of the paper after it’s been squashed flat.
Common Mistakes and How to Avoid Them
The most frequent problem beginners have with squash folds is not opening the flap wide enough before pressing down. If you try to flatten the paper while it’s only partially open, it will crumple unevenly instead of lying flat and symmetrical. Take the time to fully separate the layers and position them before you commit to creasing.
Another common issue is pressing down off-center. The fold line of the original flap needs to align precisely with the reference crease beneath it. A helpful trick is to hold the model up and look at it from the side as you open the flap. You can visually confirm the alignment before you flatten, which is much easier than trying to fix a crooked squash fold after the fact.
Thick or stiff paper makes squash folds harder because the layers resist being opened and repositioned. If you’re practicing, standard 15cm origami paper (kami) is thin and crisp enough to squash cleanly. As you get more comfortable with the motion, you can move to heavier papers that hold their shape better in finished models.