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. Seen from above, the folds spiral inward.
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. Spiral folds are common for brochures and for folding letters.
Also Known As: roll fold | barrel fold
