A concertina book is created when single or multiple pieces of paper are folded into an accordion book; it is sometimes referred to as a zig-zag. Concertina forms can be added to a sewn binding to add more dimension to a book. The artist may sew pamphlet stitches into the folds of the concertina, or glue a folded piece of paper onto a flat side of the zig-zag. This binding is particularly useful for display purposes due to its dramatic effect.