Left part of the figure shows initial z folds superimposed by z, m and s of later coaxial folds. Right hand part shows just the reverse. The s folds are superimposed by z, m and s folds of second generation fold. In this case only type 3 fold interference of the simplest type is considered. If the folding is not coaxial but departs from it there is a tendency of these patterns to show complex closure patterns.