Definition: A piece of paper folded in spiral folds has two or more parallel folds that fold in on each other. It may fold in from the left or right. To allow proper nesting of panels that fold in, inside panels are usually 1/32″ to 1/8″ smaller than outer panels with the inside end panel being the smallest.
Also Known As: roll fold | barrel fold
Examples: Seen from above, the folds spiral inward.