Squash Fold
A Squash fold is a technique used to flatten a pocket of paper into a wider shape. It is a foundational fold for some bases and more complex folds, and is often used to add symmetry to models.
In diagrams, Squash folds are normally shown with a larger arrow indicating the section to be flattened, and sometimes the newly formed creases are shown alongside.
The key here is to take care and make sure the resulting central crease lines up as shown in the diagrams.
Diagrams
