The terms 'valley' and 'mountain' fold are used to describe the direction of a fold in a piece of paper. These terms are commonly used in origami and paper folding projects. The names have been given to the folds as they best describe the way that the folds look.
Valley Fold
A valley fold is shaped like a valley or 'V' with the fold pointing down as you look at it.
Mountain Fold
A mountain fold is shaped like a mountain peak - '^' with the fold pointing upwards.
The types of fold are important for more complex paper folding projects as they enable the paper to be folded in different directions. In most projects, where the direction of a fold is important this will be clearly labeled. In the majority of the projects that you find here at About.com Rubber Stamping the direction isn't important, however where it is, you will find in the instructions reference to valley or mountain folds.
