this chair folds flat for storage and shipment , or unfolds and sets up for use , in only a few seconds . even though it is strong and stable , the chair can be made from one simple blank of five rectangular panels , two smaller panels and a glue tab , using only two glue joints . its lower part , a rectangular glued tube , has a vertical seat - support panel across the inside , parallel to two of the outer walls -- so the support panel , though preglued in place , folds and unfolds with the tube . the upper part of the chair is an extension of the tube , but the front panel folds inward , backward , and downward to form a seat that spans the tube , supported by the front and seat - support panels . refinements in support - panel detail facilitate assembly and disassembly while enhancing both support of the seat and controlled deformation of the seat and support for best comfort . the upper part of each side also folds inward and downward , but only above a diagonal fold from the upper rear corner of the chair downward and forward to meet the fold line of the front - and - seat panel . the sides double over along this diagonal fold , so the seat is in effect hung from the diagonal folds , receiving slight additional support . the back is scored to allow deformation of the tube in a buckling mode , for added comfort .