A cardboard blank has a plurality of fold lines dividing the blank into section for folding into a loose leaf folder or a box file. The fold lines define two cover sections between which there is a spine portion having multiple spine fold lines defining a binding zone which can be formed as a double thickness ridge to which papers can be attached. The fold lines additionally define various flaps which can be folded flat onto the cover portions to form a loose leaf file or which can extend to form a box shape with the cover portions and spine portion.