Interlocking : a concertina book
hand drawn ink and pen on archival paper
3 1/2" x 3 1/2"

A concertina booklet is an origami-looking pop-up book. It is called a concertina booklet because the folded structure resembles a concertina, which is an instrument similar to an accordion. It is often referred to as an accordion book.
Interlocking: a concertina book